PIONEER UNITS: Do they have any special abilities, beyond the inherent combat ability? Do they improve your chances of knocking down fort levels? How about bridging?
There is no bridging in the game per se, just a fixed cost for moving across rivers at various weather conditions.
Sapper squads improve the chance to reduce fort levels, and they also help in fort construction when adjacent to enemy units, which most squad types won't do.
SOVIET REPLACEMENTS: Playing early Axis, sometimes you have a choice between encircling a large number of Rifle divisions, or a much smaller number of Tank/Motorized divisions with much higher combat values. If you are trying to hurt the Soviets, it's kind of a choice between causing AFV/Vehicle losses, or more Manpower losses. What hurts the Soviets more, generally? Is the production bottleneck typically Manpower, or AFVs/guns?
I'd suggest going for the most damage to Soviet manpower. The Tank divisions will downgrade by themselves at some point and the motorized divisions will turn into Rifle divisions. The main problem with trying to go for AFV's in 1941 is that the vast majority of the tanks the Soviets use are outdated and no longer in production. If you knock out 500 T-34's in 1943 in a turn, they'll feel it. Knock out 500 obsolete tanks isn't really a problem. The same goes for the Axis: the Panzer I's, Panzer II's and Czech tanks are essentially just extra, they're not the AFV types that matter in the end.
RR REPAIR: The AI will send construction units from HQs to rail repair. Only problem is that they seem to want to backfill every siding and spur near the border, before repairing anything closer to the front. Is there any way to influence where the non-FBD rail repair will go?
Use a corps HQ or keep an RHG command in the rear, as the construction battalions assigned to those won't move beyond the command radius of the HQ, so they'll always repair within a 5 (corps) or 15 (army) hex radius.
WitE Alpha tester
Panzer Corps Beta tester
Unity of Command scenario designer