It certainly would be a non-trivial task since pivoting of hulls or turrets have nil cost in the SP universes physics. Nor does traversing windy mountain roads require one to slow down, and things like a fast scout car travelling say 20 hexxes on a straight road, can take a hard 90 degree left at a crossroads without braking or drifting into the field or buildings alongside...
Now, weapon slot 4 is
supposed to be a "hull gun" - and so is more restricted in arc to the front face only. However not many things (like stugs say) were
ever designed with the main gun in slot 4, not to mention the bow MG. Not by SSI in the original game, either. Nor will that
ever be "rewritten" by us as there is scads of data in all the OOBs, scenarios, campaigns and so forth that would require rehashing. Nor would it ever be going to happen, for basically not much noticeable effect in actual playing terms - there are a few tankettes that some OOB designers made that way - these arent noticeably worse than the ones with main weapon in slot 1. (We did fix the slot 4 no-traverse problem so any AAAMG fitted there can now traverse if the vehicle is disabled and cannot turn. We did that a fair few years back, but until then the turret top AAMG only could fire in the front arc iif the track was damaged).
However, in the reaction to fire, we made it so that
hull turns are in fact
more difficult especially for moving vehicles so when firing on those, you will note that the turreted ones will turn those to face the firer way more often than a stug-type vehicle will pivot the entire hull to face. Sometimes turreted vehicles will pivot the hull to turn as well - if that had been a stug, that would be the turn of the gun to face. Firing back depends on shots available - but putting thicker armour towards the shooter is good and the turreted vehicle which only turns turret to face will have a chance of the turret face being struck rather than side armour. Also - the less MP the targeted vehicle has, the less likely to turn, and a hull turn needs more remaining MP. In game terms now, a "stug" is determined by the lack of a separate turret icon, in the reaction to enemy fire sequence of the code.
And in the SP universe, anti-tank guns
all have a built in turntable that
few actually did have - the 2 pounder, 25 pounder, 88 Flak, post war the soviet 122mm D-30 and WOMBAT etc - so an 88 L71 "barn door" pirouettes nicely to react to flankers. Anti-tank gun placement is therefore way less of an issue in-game than reality.
But then again - Steel Panthers had to squeeze all the data and code into the original
640K limitations of the IBM PC of the day. It needed the addition of a 2MB(?) memory expansion card back when PBEM replay was introduced in SP-2 for that to happen, and those were a
big deal in those days!. SP1 IIRC never got PBEM replay, and hence that was a major reason for out original hacks to add WW2 toys to the SP2 engine - SP2WW2 - and so the journey began to our games and our getting the source code from SSI.
I dont like having Stugs as my bread and butter core armour in the german WW2 LC, even if they have better armour at the front than a panzer 4 (with its limitation of 5 for turret front) as they get stuck if the track is broken, and usually do so somewhere that is embarrassing..
Bottom line is that stug type vehicles that are caught in the flank
will suffer penalties and failures to face, whereas turreted ones may deal with that rather better. Stationary vehicles are more likely to hull turn to face. This all disadvantages moving stugs especially, so stugs are best used halted - ie defensively. If you do move stugs, then
try to leave a few MP free for reacting to enemy fires by turning to face, if you havent made cover!. A turretless vehicle does cost a
few points less, but the points saving is marginal overall. So turrets for the win
!