4-5 dps I just tend to blow my nuke sooner, with no healers backing them up, they're usually very easy kills.

If you'd heal and they have any form of cc, you're royally fucked. I'd suggest just nuking the shit out of them before they can do a thing. :P

That's how I win pretty much all four/five dps fights (Unless they keep lossing and I screw up at the start of the fight. But that happens more rarily every time I do arena. xD )

Seriously tho, healing against 4/5 dps teams? :s In the few secs you're healing, one will be counterspelled, another deathcoiled, another cyclowned and prolly one earthshocked as well! (Well, probably not all four, but I'd say it's easy for any opposing team to quickly cc two of your four shammies, which against a 4/5 dps team would surely mean game over in mere seconds? :P )

Just questioning your tactic. I don't see it working for me. :P

edit: Besides, you REALLY don't want to run oom before at least 3 people are dead in such comps. Too much healing would ruin your chance to win. O_o