Do you always get a set number of reinforcements in the mission Supreme?

Solution 1:

I ended up playing this mission twice because I was an idiot and missed one of the + level objectives early in the mission.

So I can confirm that you always get your army "topped off" to the appropriate level at the reinforcement spots, no matter how many of your units you've managed to lose in the meantime. It does not change with game difficulty.

• Before 1st boss; 6 Roaches
• Before 2nd boss; 6 Roaches + 4 Hydralisks
• Before 3rd boss; 6 Roaches + 4 Hydralisks + Ultralisk

Although I admit I have no idea where the reinforcement spots are in the 3rd part, because I made it all the way through without losing any units, mostly by leaving them behind and soloing most of the area with Kerrigan.

I assume there's one right before the boss though, like there is in the first two parts. I know that you do get refilled (to 6R+4H+1U) before the last boss though, because the 3rd boss's constant spawned Banelings are quite the hazard to your normal units.

Solution 2:

I was on Brutal and always got the same amount of units despite the fact that I didn't always lose all my units. Though I ended up being alone with Kerrigan more than once thanks to the ghost-tank and firebat sentry tower combo.

I would say that you get the same amount of reinforcements no matter the number of units that you have remaining.

I found this video where the guy has the same amount I did despite having surviving units.