I had a similar idea as you, and went for a mixed class team and checking every armor type and proff.

I went for an untraditional 4 char team of Paladin - Hunter - Druid - Warlock.

My initial thought was to drive and tank from the paladin, but switched to tanking from druid around SM levels as there were less mana issues and downtime that way. (Should have added a mage). This was mainly for Dungeons, but for open world questing I would swap back and use the druid as ranged dps.

Its been a slow climb (was 50 when Phase 2 hit), but loving the mixed group, even though its slower than others.