All that I am going to say is that it is a 19 twink PUG ( Pick up group). This means that teams are RANDOM. Yes a team can Q a 5 man premade. Happens a lot. Both factions. As long as you aren't stacking 3+ BMs or something stupid, I don't see a problem with it. Playing with guildies on Skype is fun. But if you have a 5 man premade of competent players (which harvest happens to have) and you pop into a game with 5 other competent alliance (which alliance sometimes has, sometimes doesn't have), and horde has a random rag-tag team of 2 rogues, warrior, warlock, mage, WW, Boomkin, shaman (not sure spec), and then nastimyt FCing/potentially solo healing, what do you expect? Or just because Blurzz and I get in the same game doesn't mean that we Qued together.
TL;DR When several competent players pop into the same game with a premade group, yes it is going to look steamroll. Hopefully it will be a quick game and a few people from the winning side will log over to the other faction. This goes for both teams.
PS: Double MW is insanely broken.
edit; It appears that horde could use some more healers, as nastimyt seems to be solo-healing in one or two of those screenshots. And as far as which faction has more healers, it is totally random. I can't count how many games I have solo healed. So yeah. There are more factors then just premade vs no premade. Yes they secure 2 heals so they don't end up in an awful game with 10 dps and no healers.