OP3 Changing 'logic' board (cpu, mem ..)

Hi,

I dropped my oneplus 3 one time to many and my screen is cracked (still working tough). I got a donor phone with a bad charging port.

I found the awesome screen replacement guide here, but seeing the whole video I was wondering:

Wouldn't it be easier to user the donor phone as my new phone, while replacing the charging port AND logic/mother board from my old phone?! (less 'screws' to undo ...).

But my biggest concern is, loss of data! Since there is no decent tool to backup android devices without your phone being rooted... ?)

thanks for the help!