I love the group initiative idea, as well as the flow of combat in LL (and thus, Classic D&D). I think it feels much more fluid and visceral than the "everyone takes a turn in order" approach of more recent versions. However, I still don't really like the idea that one side goes down the list while the other side waits for their turn. In fact, one of my favourite scenarios in combat is a tie in the initiative roll, where both sides get to act simultaneously. I know I'm being knit-picky here, but I've toyed with the idea of an alternate initiative method that would give me that chaotic, brutal feel I'm looking for in combat.
Basically, all I was thinking of doing is having all combatants perform their actions in the appropriate phase. Simply put, both sides move (in initiative order), both sides shoot (again, as per initiative), both sides cast spells, and so on. I understand that this is essentially treating combat as though a tie were always rolled, but I would NOT use the "simultaneous action" rule from the RC, which states that in case of a tie, all sides get to attack even if killed-- unless an actual tie is rolled, of course. I think that would make things insanely hard on the PCs, and make initiative nearly pointless.
On top of that, I would also add a few distinctions between melee weapons as far as speed. Essentially, a two-handed weapon always loses initiative to a one-handed weapon, and a pole arm always wins initiative against an opponent moving in. I think this would be a simple way to factor in the different speeds and maneuverability of different weapons. The guy with a halberd is going to get an attack before his foe with a short-sword closes in, but once he's within striking distance the short-sword will be way faster.
Any ideas? Possible problems I may have missed? I'm actually afraid that this will make combat extremely deadly, and especially difficult for those with ranged weapons and spells. While it will certainly drive home the importance of sound tactics in combat, as well as the necessity of a "front wall" of fighters, it may also put the party at a severe disadvantage too often (such as declaring that you will shoot, or target a monster with a spell, and having them move out of the way).
Thoughts?