You are actually showing why your point is spurious by including the heights. Every extra cm of height adds weight that isn't necessarily muscle (water, bone etc). So Parker being taller than all of those others actually means he would probably need to be significantly heavier to develop the same power-to-weight ratio as those other players.Will he though?
Jury is out whether he will make it as a second rower but size wont be the issue.
Parker is 193cm and 100kg
Cam Murray is 184cm and 95kg
Liam Martin 183cm and 103kg
Briton Nikora 185cm and 94kg
Jeremiah Nanai 186cm and 104kg
John Bateman 183cm and 96kg
Hudson Young 182cm and 98kgs
Angus Crichton 187cm and 102kgs
You can see it, too. Put Parker and Martin next to each other and you can see which one looks like he has a more powerful frame.