the Paladin has the highest actual upwards mobility class in 3.5, and they have a large number of splatbook supports that alone raise their tier, where as the second highest mobility class, Ranger, requires a specific set of books to move up on the ladder, specifically, Dragon 336 + UA + Champions of Valor. Mystic SotAO Wildshape Ranger may reach in T1 for 5 levels, but they drop down to T3 afterwards.
I also changed the names from VOP to VPC