Play what you want. You can get 30/50 using any character. Hell I play a warrior and they're so gimped at this stage of the game but I'm at 45/50... You can do whatever you want so long as you're devoted and have a good guild backing you up. If you're interested in a Speed clear / Hall of Monuments guild PM me I'll send you some details and our website (or you can see our post in the GW2 Recruitment thread). Either works and I've taken a few MMO-C members in and they've done some great things with their HoM progression ^-^