Point units (not always present, - sometimes I use the 'tip of the spear' for the same function in a non-explicit way) Company.
First Echelons Bn or Bn(-) if an explicit point unit is detached - may have reinforcements included, but I tend to keep tanks and anti-tank units concentrated into Bn sized formations as a 'fist' supporting whichever 'wing' needs support or is doing better (depending on general situation and enemy capabilities).
Follow on forces - Regt (-) or Division (-). Support Echelons concentrated under a reserve HQ and moved as required to suustain LOC links, and to avoid cross-front supply orientations - each is oriented as directly from rear to troops, with minimal lateral routeing.
Because you have some distance/time to play with, you can make your movements in column to use speed - with off-road movements planned you might prefer the additional dispersion and shorter formation depth given by wedge/successive lines, but in most cases the main body should be out of direct fire range until after the point and first echelon have developed the initial contact.
Each force is large enough to develop a basic defensive position and hold for 6-12 hrs or so, by which time one or two follow on forces can be converged on the battle, or sent via other routes to his rear areas. Artillery disrupts his reserves before they can be committed, routs any artillery or supply spotted by the lead elements, and protects the weak forward elements from being overrun if enemy presence is strong.
Administrative moves are best done by Division or Regt, but manoeuvres to contact are usually more responsive when performed as Bn or Regt (if sufficient lead time is available). Always explicitly base Regt Supply elements before using Regt forces for an attack - the AI will base them too far in the rear, and with considerable lateral offset - or if basing is off will bring them right into contact. You might also want to explicitly bring forward the AT and mortar assets - the default basing often leaves these out of a developing fight. AT guns should be dug in in the second line, and act as a stop line for tanks pressing the front line forces.