One mod of the classic minion rules I like that works well in ICRPG is a threshold variant.
The one hit point minion never sat well with me; I think it was 4e D&D that introduced these normally tough and powerful creatures in multiples retaining all of their abilities but only having 1 HP—just because they work for the BBEG and have some friends. Death slaadi should not die from a paper cut. It fractures my suspension of disbelief regardless of which side of the DM screen I am on. (I understand that there are thin justifications for this rule based on the expected damage per round output of higher-level PCs, but that reasoning only hobbles its reasonable implementation. I want a mook rule that makes sense and has universal implementation.)
The hit point threshold rule for minions I made up for my own table seems to work pretty well for me. I set a damage threshold for my minions—usually half a heart, or 5 HP, but the GM can adjust—and I kill off mooks after a single hit that meets or beats that threshold.
Got a horde of thirteen pesky goblins? No problem. Now they shrug off wimpy little hits of one or two points all day because they are tough little buggers, but they will keel over dead when somebody lands a solid hit of 5 HP or more—and the GM never has to keep track of how many hit points Goblin #7 has compared to Goblin #11. Imagine if whack-a-mole had an accelerometer.
Now the party can still wade through a flood of inferior opponents Conan-style, but there is some meaningful granularity introduced to provide some interesting texture to the event. Verisimilitude is better preserved under this threshold rule than under one-hit kills because it respects natural variation in combat and allows the GM to tailor the threshold to the encounter, but it still saves the GM time and effort while running a many-versus-many combat encounter. I think it’s a little more realistic and a lot more fun than the one hit point rule, so since it’s also less work than strict HP tracking in a horde, it’s a win-win for me. I hope other folks give it a try and see what they think of it.