Since 2021 is already over 6'1", ( he's hoping for 6'4" ) I think He's already a good height to add muscle & strength to his 160 lbs, which is the goal this winter.
2021 Mom's dad was 6' 225. Both sides have family shorter and taller than 6', but the avg is 6' + while most mothers are in ranges of 5'1"- 5'8" going back two or three generations.
Most of the kids seem to be bigger than parents on all sides except mine.but mine are all near the same size. Girls and boys.
We just got done with Legion and now the fall team 2021 plays on will travel down to AZ to play in Oct (AZ Senior Fall Classic) is practicing on the weekends.High School has started and basketball open gym (to which he said , I'm not playing ,just practicing..... we will see...) are going on. I finally get to relax and do the yard work & honey-dos I sorely missed from coaching this year.
Definitely you have a good size family and just eyeballing, most of your kids will be over 6', with good nutrition more inches will follow. But some people might think because you are 6'5', they are getting your height, of course there are other factors as well. I have a friend he is 6'8", and the doctors are projecting his son to be 6'9", there is no one in the wife's family that is remotely that tall, maybe few 6s.