I have 5 matches with a y-37 test with only three str exceptions the one that I was hoping to learn more about is str 458, my 458=19, the other 5 have an 458=18. The 5 are all related as father son brother uncle. We match 24 of 25 strs and 34 of 37 strs. We share the same surname and haplogroup and are trying to establish how we are related. In terms of sharing an ancestor can a prediction be made based on one str how many generations back we would need to go? Or is str 458 telling me something different?

Thanks for helping!