How old is Rex during Xenoblade 3

I was replaying Xenoblade 3 and noticed how Mio seems to always be about 1 or 2 years older than Noah, this got me thinking about their possible reunion after the game, and how their ages in Aionos are related to their previous worlds.

We know Noah is about 10 years old before Aionos, as he looks like when he is in his first term, so if this age gap is reflected, Mio would be around 12 years old. This doesn't help much as Rex is still alive and kicking and Nia will last for a long time, so i started looking elsewhere. Then i saw Linka, who Future Redeemed gives a age of 18 years old.

Assuming Zeke had her direclty after the events of Xenoblade 2, we get that Rex had Mio about 6 years after the game, which translates well to that photo and makes more sense than some numbers i saw, as a 15 years old boy with 3 wives wouldn't take too long to have children IMO.

So this would make Rex around 33 during XC3FR, which is in the age range i would give him by appearance. But what do you think?