Firtst just by means fo official confirmation you never roll dice against overlaps - they get all the pleasure againts you.Code:
__AABB
1122
All of the dice from BG A are against BG 2 and vice versa. 1 and B both get to add 2 dice to the combat without reply. As a result both A and 2 could end up losing the combat due to hits from the overlaps.
As for the above a very reasonable scenario I have seen several times.
AA = LF
22 = LF
BB = Armoured Cav
11 = legionaries
Seemed perfectly reasonable that both AA and 22 got hammered while drawing amongst themselves.
On the pursuit issue we felt it was the best balance to leave it this way. If BB is brave enough and agile enough it can turn around and try to interfere/take advatange of the pursuit. But imagine BB was LF and the others were knights. It would make no sense for the knights to stop at all due to a skirmish overlap (and these oare often committed to gain an extra dice). We also need to remember that a BG or base is not a small space so most of the pusruing BG is running of in pursuit perhaps 100 yds from the overlap, who will in practice be busy trying to disengage and reset themselves having seen their friends crack. It is not a base but 250 indiviudal dots. I am sure 30-40 would be left fighting the voerlap but its not worth replicating at this level.
We did consider having pursuits slowed by 1 MU for each overlap in existence. But ditched it pretty quickly as an unnecessary complication that added little and would often get forgotten anyway.
Si