I actually don't mind frequent POV shifts, because that isn't how I define "head-hopping." To me, head-hopping occurs when the reader ISN'T CLEAR on who is speaking. It's not just an issue of "Bob thought this" and then "Tom thought that" but more this sort of thing:
"Do you want to go to the store with me?" Lips twisted with loathing, he walked away.
So who made the motions? The speaker or the listener? It could be either the way it's written, and since the words don't really match the facial or body movements, you're left scratching your head. THAT'S head-hopping to me and it's what editors loathe.
But with proper attribution of:
"Do you want to go to the store with me?" He barely noticed Tom's lips twisting with loathing as he walked away.
Now it's obviously in Bob's POV. He's NOTICING the actions rather than making them.
JMHO, of course. But unclear actions are what make head-hopping for me, not merely frequent POV shifts.