I'm sure tactics would be developed to match any change in the rules. But it seems likely that the winning tactic would be likely to involve a kind of ping-pong afair with goalhangers at both ends paired off with hatchet-men dfenders, and a succesion of long balls from end to end.

It might be interesting to find out, but the best way might be to have a breakaway league playing a modified code, the same way you have two codes in Rugby.