Characters with 4 Health Bars

Is there a reason why all the fusion characters have 4 full health bars and not two? Isn’t the whole point of the fusion to deliver a lot of power over a short fight? Why would Gogeta have more health than any of the Buu variants? For that matter why does UI Goku have 4? I think they should retool the health system in this game and it might solve the Ranked problems some.