The Guardian theme lets you punish one attack against your allies per encounter, no mark needed. It's a solid choice for anyone who likes making extra attacks anyway, and it's doubly nice if you need more stickiness. Also, damn near every character with a decent MBA can benefit from taking the (MC Fighter) feat Battle Awareness, which also lets you punish one shift or one attack against your allies per encounter, no mark needed.

Cavaliers still suck at defending, of course, and if you can get away with swapping your class to be a true Paladin or a different defender, you're going to be better off for it. But Guardian and Battle Awareness are a pretty nice band-aid.