That's funny - we were trained to keep upright till the section commander issued the command "Take Cover!" -
only then would you do the "dash, down, find cover, observe, return fire" battle drill initiated by the "Take Cover" command issued by him. Taking cover wasn't up to individual soldiers to do on their own initiative (though in reality of course if fire came a wee bit close, he was going to do something about it!
)
The troops may be in terrain cover, but the action of taking cover is entirely separate to their being in say woodland terrain.
Infantry in the game already can take cover (an active action) as a result of taking fire - you will see the "X takes cover" message, and if successful they may break LOS, as well as breaking the chain of fire.
The take cover command is there as a
voluntary action in case (or if you are certain) that you have been spotted, the unit then attempts to take cover (or if already down, wiggles to a new fire position, hopefully not spotted).
It has nothing to do with being in cover terrain whatsoever (although it
will be easier to go into cover if in covering terrain). And there is no such thing as "no cover to be had" - flat terrain will have lumps and bumps, individual bushes or rocks etc that provide cover. Flat terrain is not a lawnmowered golf course - think of it more as the rough (as found in a Scottish Golf course, not one of those manicured golf courses).