The armor mechanic acts on the last 500 Health, regardless of predator or private match setting. It’s also a straight slope from 100% - 75% damage taken.
So it’s roughly equivalent to 500/0.875=571.4
Add the rest of the health for 1071.4
Scout 0.91 bullet resistance.
1071.4/0.91=1177.36
Impen 0.8 Damage
1177.36/0.8=1471.7
Scout with Impen ~ 1472 effective Health
City Hunter also gets .933 damage multiplier and the armor mechanic.
1250 base
1321.4 with armor mechanic
1416.29 with bullet resistance
Scout with Impen 1472
City Hunter Base 1416
Less than 4% more effective health for Scout