I think I'd mentioned the ruleset for retainers earlier, but the quick breakdown is below. Don't feel like you need to commit this to memory or anything, it should be simple to run, just giving you the 'behind the screen' mechanics so you've got expectations:
- Have Health Levels, not HP, so no need to track every last bit of damage or healing
- Each time they get hit by an attack, they make a Con Save vs average damage as DC. On a fail, they lose HL scaled by damage die
- HL can be regained 1/ short rest, and each die of healing magic regains 1 HL
- Initiative is shared with you, and if you hit, they hit, though it can be on a different target. If you miss, then you can roll to see if they hit
- Saves vs damaging spells, lose half spell level in HL on success, spell level in HL on fail
- Signature attacks and special actions: Have a regular attack, and then some number of actions that can be taken. Special actions are limited to once per 10 minutes (encounter), and may be limited to a certain number of times per day.
((Just saw retainers are supposed to cap at 7... with it being a squad, I think 8 will be fine.))