It's not so bad. As long as you have a partner about your level, you'll find Marleybone quite easy at first. Be careful, you would wanna be a mid-magus at Big Ben, and with 3 partners. It's a challenge.
i think your fine as long as you have good stats and good health and mana not really depending on the level. Really you have to have good stats and i have a life wiz in mb at lvl 23 and he doing fine so i odnt think you are to low