Kevin Constantine has had three different NHL jobs in the past so we'll use the same comparison that we've used for Quinn, Renney and Crawford (in order of desirability). That means we'll be comparing his record to those coaches he preceded or followed (hat tip for the methodology to the Contrarian Goaltender):

One thing you'll notice if you've looked at some of the other coaching posts is that this one has two extra columns. That's because the difference between George Kingston and Kevin Constantine is ridiculous. In fact, it's the biggest point difference season over season in history. On the one hand, that's a credit to Constantine. On the other hand, it might obscure the exercise a bit. It turns out he outperforms the other coaches by a pretty significant margin even without Kingston. The other coaches are Pat Burns (82 games), Herb Brooks (57 games), Jim Wiley (57 games), Larry Robinson (51 games) and Craig Patrick (20 games).
In addition to his good performance by this measure there are some other indications that Constantine is a quality coach. He was the coach of the Everett Silvertips in their expansion season and led the team to a division title as well as the best record ever for an expansion team in any of the CHL leagues. The team went all the way to the WHL finals and Constantine won the award for coach of the year. Later in his coaching tenure he was suspended by the league for four games for cruel and unusual punishment. Robert Nilsson may need to worry about his puckbunny privileges.
After his stop in Everett Constantine moved on to coach the Houston Aeros who are currently in the second round of the AHL playoffs. I haven't heard a lot of buzz around Constantine since he was mentioned by Jonathan Willis shortly after MacTavish was let go. Still, he's a former NHL coach that's currently coaching a playoff team from outside of the organization. That fits well with the resume I imagine Tambellini has in mind. That said, I don't think Tambellini and Constantine have much history and Constantine certainly doesn't play an up tempo style. Further, given that the Aeros are the affiliate of the Minnesota Wild, I'd think that Constantine is probably a good candidate for the head job there (though if he gets it, I'd imagine we won't be worrying about Gaborik six times a year). If he doesn't get that job, I would definitely endorse his hiring in Edmonton. If his hockey victories are anything like his military victories of the 4th century the Oilers should be in good shape.