Just don't be armor reliant. You'll be fine.
^ Horse.
This suggestion is totally against the anti-specialization trend that's going on.
I must disagree. Anti-specialization measures thus far have been good, keeping powerbuilds and one-trick pwnies down. This suggestion does nothing to the changes in WPF, nor does it go across the board and reduce all upkeep rates. Players can still be of whatever mix of roles they want. However your example (who sounds exactly like my build sans horse) suffers under the current system because he cannot develop any further than vanilla equipment. Imagine if instead of wearing low level mail he was able to wear plate because he had a 50% discount on it. He can't wear high end plate all the time because he's not getting his armor slot for free, but he can save up and invest for one good piece of gear. Or maybe he'd rather keep wearing mail and get a horse at 50%. Now he's effective light cavalry and can fight even in the 1x multiplier when his team is hurting and needs something to turn the game around. Or he can keep wearing his mail and break out a big poleaxe at 50%, turning from a support trooper to the tin-can killer needed to kill enemies with a high multiplier.
It would further encourage the heroes spawning naked with their triple-heirloomed super sword and nerf the medium tier guy that's trying to be useful to his team by carrying a basic shield and spear for support and some other mid-tier weapon for finishing touches.
As I've explained, there's just no reason how this encourages 'hero' players (who now face better armored enemies and more powerful archers,
discouraging them) nor nerfs a medium tier guy being useful. He can now be more useful!