Let us for one second assume that Bruce Pearl has no real loyalty to Tennessee other than his current paycheck and as a stepping stone to his next job. This Bruce Pearl would have to be very careful about job-hopping too much. He's garnered a lot of national attention for both himself and the program because of the way he's relentlessly promoted Tennessee: the orange blazers, the chest-painting, the reciprocal Pat Summitt stunt, etc. The media has by and large thought all this is great because in this day and age, a little old-fashioned school spirit is a rare and kind of cool thing.
The problem is that he can't really go somewhere else and do it all over again without looking like a cynical, opportunistic Nick Saban type. If after all that supposed unabashed love for UT, he leaves after only two years and goes to the first job that comes along, the media will absolutely kill him for it. No more chummy chats on PTI, etc.
Therefore, this more cynical Bruce Pearl would need to be careful about changing jobs very often, because his whole appeal will shrivel up and blow away. He would need to make sure that each change was a step up, either in prestige or money. Iowa is neither (assuming UT would match whatever they offered him, unless it was ridiculous).
Fortunately, I don't think it makes a difference, because I don't think that's who Bruce Pearl is. The only way the Iowa job makes sense -- either for the real Bruce Pearl or his sinister alter-ego -- is if he either has a real emotional attachment to the Iowa program, or if they offer him an astronomical, idiotic amount of money. You can't compete with either of those.
I don't think we have anything to worry about.