I say that physicists are smarter than mathematicians. You say?
As a mathematician I find this question vaguely formulated. Which criteria should one use to decide whether a group of people is more intelligent than another group of people, the average IQ of the group, the highest IQ in a group? As far as the two groups mentioned in the question there are “embarrassing” situations such as, Edward Witten, a physicist being awarded the Fields prize for mathematics and Sir Roger Penrose, a mathematician being awarded the Nobel Prize for physics.
Philosophy is harder than both. The first rule of philosophy is you can never know anything for certain. Tell a mathematician this, and they will lose their mind. Tell a classical physicists this, and they will quit. Tell a quantum physicist this...they will laugh, and say what's new? What's easier? Walking around in a "dim" room, but being able to barley see.(mathematics, and physics). Or walking around in a room that is so dark you cannot see at all? "Faith"....is the hardest of things to hold. Mathematicians, and physicist have no need of faith...so they think....