I can imagine that's a technical compromise. It's easier to put a hat model on a person model than a tight fitting swimsuit around a seperate face?

You're right, i checked for myself and i can confirm this too. No matter what face you choose your character to have when using the CSAT wetsuit you will always end up with this face. Other wetsuits allow custom character faces.

Still observed in 1.36 stable. Not a big problem though.

This is still an issue in 1.40 stable. Again, it only affects the CSAT wetsuit.

Also all of the models seem to have a misaligned vertex for the left arm. Whenever the unit uses an animation that flexes the left arm, the vertex clips all the way into the model's chest or stretches into the head when idle.

Wetsuit [NATO] - http://i.imgur.com/szDY7PC.jpg
Wetsuit [CSAT] - http://i.imgur.com/Y8RUbHO.jpg
Wetsuit [AAF] - http://i.imgur.com/mkOzyU8.jpg

Both bugs are still present on 1.42.

Issue still remains on 1.44 stable.

After tinkering around with the config, this issue is caused because the base class for OPFOR divers (O_Soldier_diver_base_F) does not have the selectionPersonality parameter defined.

A very simple custom config addon that adds selectionPersonality = "personality"; to the base class automatically fixes this issue:
http://i.imgur.com/0dqaDxo.jpg

On a side note, the vertex bug with the model itself still has not been fixed.

Issue still remains on 1.46 stable.

Should be fixed in the next dev branch update. Marking as resolved.