I've lost a number of AVs, where my side was well ahead but did not have a tank option.
An undefended Galv/Belinda shouldn't be an issue with 10 characters, even early in an expansion.
Drek/Vandar, with two towers/bunkers down and other players for support, will likely still require a dedicated tank + healer.

Team A: Blood DK & Holy Paladin, with 5x Battle Healer Rets in the mix.
Team B: Glyph of Demon Hunting (http://www.wowhead.com/spell=64318) on some warlocks & 3x Healers.
Team C: Heart of the Wild (http://www.wowhead.com/spell=108288) on some druids, plus the above listed Feral options.
Team D: Options...



Team D
a) 8x Elemental Shaman, plus Druid Tank (Guardian or Heart of the Wild - Boomkin) & Priest Healer (Mass Dispel).
b) 9x Shaman (some Resto), plus the Druid Tank.
c) 10x Shaman (some Resto), with 10x Fire/Earth Elementals...

How well/poorly do 10x Earth Elementals fare, against Drek/Vandar (or the IoC Generals), especially early in an expansion?
Would a Druid (Guardian in 5.0/5.1; Boomkin with Heart of the Wild in 5.2/5.3) be a better option?
Although a Resto Shaman can heal as well, is Mass Dispel worth enough to include a Priest on the team?