So i did half a morning of trial and error in the Editor to make Female soldiers an option in missions and not a must have. The point being, that if you chose a female soldier as your profile you'd get a female soldier in a mission and if you didn't, you get a male soldier. As far as i can tell it works just fine (even uninstalled FEMAL3, launched the mission again and didn't even notice anything though the INIT line of my unit was still there).
So basically it won't make any trouble to those not having FEMAL3 installed (though imho i think everyone should have FEMAL3 and it's sad that female soldiers weren't an option in the game from the start on) and those that have FEMAL3 installed will get females as player if they set up their Profile that way.
But first of all a big Thank you to Jona336 for giving me the jump start =)


Script example for Optional Female Soldiers (to put in the INIT field of a (Playable)Unit)

if
((face this == "Oakes") or
(face this == "Tyler") or
(face this == "Tyler_scars") or
(face this == "Mason") or
(face this == "Mason_camo") or
(face this == "Mason_Rigged") or
(face this == "Mason_scars") or
(face this == "Smith") or
(face this == "Cheung") or
(face this == "Quereshi"))
then {this forceAddUniform "FEMAL3UNIFORM";}
else { this forceAddUniform "ARMA3UNIFORM";};

This will check if player has selected one of the female faces and then give them a FEMAL3 Uniform, if the check is negative it will just give him a ARMA3 Uniform


============================NATO==================================

Combat Uniform MTP (Nato) (Rolled Arms)
"U_B_CombatUniform_mcam_vest" // Male
"B_FEM_NATO_Rolled" // FEMAL3


Combat Uniform MTP (Nato)
"U_B_CombatUniform_mcam" // Male
"B_FEM_NATO_long" // FEMAL3
"B_FEM_NATO_Collar" // FEMAL3 with Collar


Combat Uniform MTP (Nato) (T-Shirt)
"U_B_CombatUniform_mcam_tshirt" //Male
"B_FEM_NATO" //FEMAL3

============================CSAT===================================

Combat Uniform Hex-Camo (CSAT)
"U_O_CombatUniform_ocamo" //Male
"O_FEM_CSAT_Long" //FEMAL3


Combat Uniform Hex-Camo (CSAT) (Rolled Arms)
// no Male version
"O_FEM_CSAT_Rolled" //FEMAL3


Combat Uniform Hex-Camo (CSAT) (T-Shirt)
// no Male version
"O_FEM_CSAT" //FEMAL3

============================AAF====================================

Combat Uniform AAF
"U_I_CombatUniform" //Male
"I_FEM_AAF_long" //FEMAL3


Combat Uniform AAF (Rolled Arms)
"U_I_CombatUniform_shortsleeve" //Male
"B_FEM_AAF_Rolled" //FEMAL3


Combat Uniform AAF (T-Shirt)
//no Male version
"I_FEM_AAF" //FEMAL3

=========================GUERILLA==================================

"U_BG_Guerilla2_1" //Closest Male resemblance
"B_FEM_FIA" //Femal3


I tested it with a small mission (basically just a soldier spawning somewhere and doing nothing) and it worked like a charm. I uninstalled FEMAL3 to test if i get some error messages but nothing happened. Only thing notable is, that there is a small hickup (really really small, like 1 second) after the spawning, probably because of the whole checking for faces but im not sure of that.

Of course i can theoretically think of an more elegant way to do it, but it would need a Scripting guru to make a real, fully functional Compatibility script to run in the backround or so...and im more like a full hardcore noob to pretty much the whole ARMA3 scripting...so i'll leave that to someone more experienced ^^

so far
Have a nice Day
Daec_G3R