thank you so much! yes, i’ve allowed players to split or combine attacks as they wish—the default in the LBBs is that characters have 1 attack per hit die (against regular figures), so the idea is just that you can choose to combine them instead though you are not forced to.
i probably would not allow monsters who already have multiple attacks or damage dice to keep them; instead, i would consider that to be encapsulated/replaced by the simple skirmish system which just looks at their hit dice.