Of the 3 you listed for PVE I would do:

War/pally(healing)/3xmage

Though I would consider swapping an Warlock for a Mage though for utility of summoning and stones/etc.

A lot of people are doing 3 Warriors and 2 Paladins so that they have 2 healers for Open World PVP.

For PVE they are planning on running the 3 Warriors in DPS mode only swapping to Sheild on a warrior who has high incoming damage.

You can review a summary of what people are thinking/planning here:

https://www.dual-boxing.com/threads/...Multibox-Teams

Much discussion in the various threads.