Here's why I say 4.5 on the second one. That last cusp of the back molar. I personally think that is a very good indicator when the wear is well defined (sometimes the cusp is small and the wear not well defined). 2 yro....concave; 3 yro....flat; 4 yro...slopes down sharply.
On the 2nd jawbone the very last cusp slopes down sharply, and although the rest of the wear is moderate enough to indicate 3 yro, that clue alone leads me to say 4 yro.
I bet the physical development of the deer will corroborate 4 yro. Any pics?