Resources

When I look at League of Legends I see an unbelievable thing on resources. Most of the champions use mana, which they have to carefully spend in order to have enough mana to use for a team fight or gank. These champions have to invest a lot of gold into mana pools which would otherwise be spent into building damage. But then there are the special few which don't have this problem. Either they don't use a resource or they have energy, which regenerates at an absurd rate. Now I think I get the idea with energy which is that you can do a huge burst of damage in a short amount of time and you have to manage that during the fight. But here's the thing; Characters with energy can also harass much better than characters that don't. They have a more linearized item build as well giving them the ability to spend more gold into doing damage [or whatever their specialization happens to be]. This wouldn't be much of a problem, except that the energy based champions don't feel like they have the disadvantage during a team fight. Ergo, the energy comes back too fast removing the trade off of carefully managed burst damage and constant harassment. Does anyone else see this as a problem? If so, how would you fix it? If not, why not? Discuss.