Some notes.
Not that I'm an expert, but I have been part of a tabletop group that has just got characters to level 5 from level 1, so have seen many many combats and synergies between all character types.
Defenders (including Paladins) have an INSANE number of healing surges... which makes Paladins better, in a way, since they can use some of those surges for others, but their marking works a little different. The Paladin isn't going to do the damage of the strikers, their role is to keep some of the bad guys on them, and if you're using that strategy you will excel.
Karis and Rellek are the damage dealers, and especially in the case of Karis, that damage most likely comes in the form of up close and personal, which makes combat advantage a great benefit, which is why Todarr keeps charging in and getting stuck multiple multiple times, because the shifting and such I can do can keep the bad guys surrounded. And I have an encounter power I haven't used much that does a good hit, then allows an adjacent ally to make a basic melee attack IN ADDITION.... FOR FREE!!! So I charge in. But it hurts. A lot.
Lotus, if you are having trouble with Moreen feeling one-dimensional.... if that feeling comes from what you're saying that Moreen was originally designed to be a caster, and was redesigned as a Paladin, then maybe Moreen is supposed to be a cleric???
Would you like to be the cleric, not the fighter, and Todarr be the fighter, not the warlord??? Let me be clear: I have thoroughly enjoyed being the tactician (and please let me know if anyone feels I'm throwing around my orders too much, I have enjoyed it but can take it down a notch if requested), and don't necessarily WANT this change, but (and of course with DM approval), Todarr as a frontline sticky fighter isn't that much of a change, really. Whereas Moreen as a cleric would be very different, but if you want to at least try it out, let us know.