There are some uniforms with too little and some with too much armor. Even one uniform with face protection. Obviously a big factor when it comes to fair PvP.

Proof: https://www.youtube.com/watch?v=5t8joAvgIH8

Combat Fatigues (MTP) have normal armor and serve as a reference point in this video. Every other uniform apart from the stronger CSAT uniforms and these broken uniforms have the same armor as the Combat Fatigues (MTP).
All the LDF uniforms except for the Heli Pilot Coverall [LDF], the CBRN suit [LDF] and the Combat fatigues (Sweater) [LDF] have the same armor as the Special Purpose Suit, which is too much considering LDF already owns armored vests. They lose less total health overall, though their individual body parts lose the correct amount of health.
The paramilitary garb (shirt) has face protection, but only if you wear a helmet. The whole head just copies the same level of protection from the currently worn helmet, even at places the helmet doesn't cover.

Here is a list of those broken uniforms:

Uniforms with too little armor:
Worn Combat Fatigues (Kerry)
Pilot Coveralls [NATO]
Pilot Coveralls [AAF]
Heli Pilot Coveralls [NATO]
Heli Pilot Coveralls [AAF]
Heli Pilot Coveralls [LDF]
Guerilla Uniform

Uniforms with too much armor:
Combat Fatigues [LDF]
Combat Fatigues (Tank Top) [LDF]
Combat Fatigues (Rolled-up) [LDF]
Combat Fatigues Officer [LDF]

Uniforms with face protection:
Paramilitary Garb (Shirt)