Folks forget that a 4 year old buck in Grayson county looks completely different than one standing in Live Oak county, or Bowie county vs Childress county, or Jefferson county vs Tom Green county.
I think the OP is much better at judging age than he gives himself credit for.
I agree with you that deer in different areas of the state certainly can look a bit different but I see absolutely no way this deer is 4.5, much less 3.5...…..5.5 certainly possible.
He is way too 'chesty' to be any younger than 5.5 I think.
I wasn't trying to start an argument, I say completely different, you say a bit different.
Bucks in different areas of the same county can look completely different.
IMO,
without knowing what county the buck is in and then what fairly specific part of that county my guess is a healthy 4, quite possibly his 5th year.
I was just giving the OP a vote of confidence in his ability to guess age from a picture.
He's doing a fine job in my opinion.