By providing the ability to specify equipment oredicts, this would save a lot of repetitions of the same armor pieces (like grouping iron and chainmail, or grouping early game helmets). Could be specified by checking if the innerTokens[0] was "ore" like

EarlyGameHelms, ore:earlyGameHelms

Set Bonus now has native support for oredict in the latest versions...and regex, too...and oredict regex! See the new equipment config comments for details if you're still interested

For anyone else reading I discussed a possible solution here:
#21 (comment)

You could just have generic.armor >= 15 and most early-game armor would work, Any armor amount that adds up to 15 or lower would count
(A full set of Leather = 7, Gold = 11, Chainmail = 12, Iron = 15, etc.)

With 15 the bar is set quite high though, A Diamond set that omits Leggings would still only reach 14. Defeating the purpose.

So Your post is still a valid suggestion