A top armour hit takes angle into account as well - just like a side armour shot does. So it can generate rather more resistance than you thought at longer ranges - that "2" can get an effective or 6 armour at long range, as the shell will have a bad angle of fall. Topshots are really only good in rather close.
Says Andy, whose A13s were up on top of some hills shooting down at Italian M13/40s at 1000-1200 yards the other week, and getting top hits with 6 resistance for the top hit shots
Side armour is rather important - it is why the Tiger and Churchill types of tank do well in combat. (Its also a big area, which is why side armour is charged more in the cost calculator). Plenty of bounces from glancing blows to the side, whereas tanks with thin tin on the side (P3, 4, Panther say) - are gloriously easy to kill if you 'fork' them - my tactic in the desert for P3 elimination, is a small armour force in the middle, and 2 larger forces working each flank - if Jerry turns South to engage force A's fire, I switch to force B who should now have a 1000 metre shot at the side, and with even 2 pounders - side hits toast the panzers, even the later model ones with 7 or 8 on the front have this Achilles flank.
The Panzer 3 has a nice feature - it has quite a tough little set of buttocks on it, and so it can run away with relative impunity from any 'up the kilt' shots
! (Achilles flank, but not his heel problem)
Cheers
Andy