EFM works great, but there are a few glaring issues that I would like to address. I will address the issue and then offer a few solutions and mainly ideas for it.

The first issue mainly applies to AI type, specifically the ZOMBIE, holding weapons.

Issue 1) EFM does not handle big crowded enemies well. Especially zombie ai type wielding swords and other tools.
-What I mean by this is, that their attacks are constant and never ending, there is little you can do to hold them back other than backing away or rolling and stepping, even then the roll and step costs so much stamina that you can only do it 1 or 2 times before having to back peddle, attack, roll back and back peddle to avoid being hit locked to death and repeat. This is extremely tedious and repetitive, which takes the fun away. TLDR: They attack non interrupted at the same time, while charging directly at you in a LINE.
-This causes the issue of you being Hit/stun locked
-Stamina depleted extremely quick if blocking to avoid damage
-Rolling/Stepping doesn't matter in this situation because they just keep walking towards you in a line and if you get close to them, they all attack simultaneously. And the mobs attacks can still hit since they have high reach because they have swords and take a huge chunk of health when backing away.
-Their non-interruptable attacks make it extremely hard to hit them in a huge group, as almost all of them are constantly attacking you without interruption, thus making taking on big groups near impossible. I understand that in most cases your FIRST attack at a mob will trigger a hurt animation from most mobs, however, it doesnt matter because they continue their attacks almost immediately in an un-interruptable fashion.
-Shields are broken extremely fast due to their non stopping attack pattern.

The main issue boils down to the attack pattern of the enemy wielding a weapon. They are in a too rapid succession with very short breaks.

I will now provide solutions, with varying complexities to them.

Solution 1: Make the enemy ai take a "Rest" after a few attack sequences are completed to increase their downtime and not constantly bombard the player with attacks. This allows us to take a breather when dealing with large groups of mobs because we can wait till they complete their attack sequencens before going in and attacking them.

Solution 2: Give the enemy AI type the ability to "Combo" their attacks, make the downtime be reasonable and their number of attacks and the speed at which they attack also be reasonable. EXAMPLE: A Zombie with a sword can execute a 3 hit combo, and after the sequence is completed the AI cannot attack for 1 or 2 seconds. And maybe interrupting the sequence in between the swings can stun the AI for 1 or 2 seconds. This helps prevent the AI from attacking non-stop with no downtime inbetween.

Solution 3: Give us the ability to interrupt an enemy before they can fully swing, whats in the base game is too little to matter to ai with weapons in a group. This atleast gives us the ability to dive in a group and actually being able to attack them without getting torn to shreds. If you think this will make 1 on 1 combat too easy, maybe it will, however, maybe you can also implement special attacks to the AI that cant be interrupted/blocked with skill or shield like the game Sekiro:Shadows die twice, so we have no choice but to back away. OR you can make player attacks cost stamina too.

Solution 4: In a huge group of enemies, make it so that only 3 or 4 is attacking/OR/engaging you at the same time. Preferrably the group of enemies surround you and move around you as opposed to charging at you in a big line (I don't know if that will be too hard to implement in minecraft) and only a few periodically take jabs at you. Like in the games; Assassins Creed, Batman Arkham series and Spiderman ps4, where there are large groups of enemies but only 3 or 4 attack you at any given time.

This is the main issue I have with this mod, that huge groups of enemies are kind of stupid to deal with(10+ mobs) specially custom enemies with ai that are wielding weapons. Otherwise a very solid combat system.

Issue 2) Rework the stamina system and its stamina costs or give us the ability to configure stamina costs and value. Stamina feels pretty unpolished and costly IMO, it can be fixed by:

Solution 1: Giving us the ability to configure how much stamina we have and how much stamina actions can cost. Like attacks, sprinting, rolling, stepping, blocking and other stuff. Maybe add stamina drains to attacks and sprinting.

A pretty straight-forward issue. The reason I ask for this is that rolling and stepping feels horrible. And the extreme stamina costs doesn't help, specially when wearing armor. When I try to dodge, I find myself getting hit before I can do so, which brings me to the next issue.

Issue 3) Rolling/Stepping having an animation delay of sorts OR the invincibility frames are delayed. I tested this in single player, and I'm pretty sure there is a small delay of some kind when pressing SHIFT to roll/step from harm. For example, when I'm rolling from an enemy when I think theyre about to attack, I roll away without damage. However, when trying to roll away from an enemy that's in middle of their swing, I sometimes get hit EVEN THOUGH I pressed shift BEFORE taking any damage. So I'm pretty sure there is a delay either in the animation time or the invincibility frames.

Solution 1: Make the rolling/Stepping animation take place the INSTANT you press SHIFT. Or in the case that it's the invicibility frames that are behind make it so that you are invincible the instant you press SHIFT. Doing so would make frame perfect dodges possible and make the dodges more snappier and smoother for an overall smoother combat experience.

Solution 2: Incase that the delay is intentional, make it configurable for those who want it to be more snappy. More configuration is never a bad thing.

These are all the issues that I have come across, I would like to make a few suggestions in here aswell.

Suggestion 1): Make new AI type for Human type enemies, that can use weapons in the same combo manner as players.

Suggestion 2): Light armor and Heavy armor system, I understand this is present in the weight system but you can go further, make using no armor or very light armor actually worthwhile(As opposed to dodging 3 or 4 times and then taking a million damage from one hit)

Suggestion 3) Add combo's to enemies to make their attacks cease after a sequence of set attacks, and then repeat. As opposed to the unending barrage of the base mod. And add combo breakers. Pretty much same as Solution 1 and Solution 2 from issue 1.

Suggestion 4) Grouping mechanics like surrounding the player in a group and engaging/attacking the player 3 or 4 at a time (can be configureable) . Pretty much same as Solution 3 and 4 as issue 1.

Suggestion 5) More configuration options. Like having an option in Auto Switching Items that makes it be able to send you into battle mode when its selected and sending you into mining mode when its de-selected. As opposed to selecting an items that takes you into battle mode and an item that brings you into mining mode, which can be a long and tedious process to setup rather than just selecting key weapon items.

Suggestion 6) This is pretty much wishful thinking but do you think you would be able to work with other mod authors like Ice and Fire and others to make the mod more compatible with it, item wise and AI wise?

Thats pretty much it. I've thought long and hard about the issues and solutions and suggestions and tested them many times. A response would be much appreciated, Thanks in advance.

@Yesssssman have you given this some thought