One 8-stand gallic warband (with a 4-base frontage) is in melee with two different 4-stand Roman hastati battlegroups (each with a 2-base frontage). In the melee phase the gallic warband deals a total of 4 hits (2 on each of the Roman battlegroups). Each Roman battlegroup deals 2 hits on the gauls (for a total of 4 hits). Both sides have 4-hits, so the combat is a draw.
Because the gauls are a single battlegroup, they have a take a single death test for the 4 hits (since the combat was a draw it will be at a +2 modifier). They will lose a stand if they roll a 1 or a 2 (33% chance to lose a stand).
Since the Romans are two different battlegroups (each taking 2 hits) they roll their death tests separately. Because the combat was a draw they add +2 to their die-rolls, so there is no way for either of them to lose a stand.
Am I doing this properly? If so, It seems to unfairly punish the larger battlegroup (or unfairly reward the smaller, depending on how you look at it). I had this exact situation happen in a game 3-turns in a row, and each time the Gauls rolled a 1 or 2 on the death test and lost a stand while the Romans didn't even have to roll. Not that it happens every game but it was still pretty annoying.
I would expect the Roman player to have to take a death test on 4 hits just like the Gauls (since both sides took 4 hits), and if the Roman player rolls a 1 or 2 he would get to pick which battlegroup lost the stand.
Either that or let the Warband armies take 4-stand battlegroups too

On further searching of the forum it seems as if this issue has come up before in regards to shooting:
viewtopic.php?f=114&t=20318&p=299657&hi ... ll#p299657
Seems as if people think the smaller battlegroups suffer in other ways so it should balance out. Not sure I agree, but whatever... it's a game.