I think warriors are a little too strong even, but if jumping or backstabbing gets toned down, it'll be more balanced imo. In any case, if you're having trouble, I'd just go for a simple, straight forward warrior build.
The PnP game sees a lot of people unused to the system complain about how Fighters are over-powered. It's an easy opinion to form when they are in full plate with Heavy Armour Master feat, killing enemies with a single sweep of their greatsword and soaking up the damage with their huge pool of hit points. Our group includes such a Fighter, a halfling in fact, and the GM keeps trying to beat the character down and generally fails.
The GM is relatively new, and was almost wiping out the rest of the party with ever-increasing challenges aimed at the Fighter but inevitably affecting the rest of us. Playing a wizard (a wizened hag living alone in a rude hut), I asked if I could demonstrate to him how he was taking the wrong approach. With the agreement of the rest of the party, therefore, my new wizard (new to the group, she was created at 10th level to fit the rest of the party) was introduced as a possible potential enemy and they surged forward to capture her.
One 'Dominate Person' on the low-WIS saving throw Fighter later, and the party were in chaos while my wizard cackled madly from a safe spot hiding with Greater Invisibility.
The point of this is that all characters have their weak spots, and it is not generally that some are overpowered, but that the challenges they are facing are ones they are designed to take on. That's the core of the D&D party system - you need characters who can overcome all manner of challenge.
