Tactician Afffinity Corresponding With Charcter Affinity

Hello I am messing around with FE7 on FEbuilder and I was wondering if there was some way or a code I could implement that would allow me to make any character, Lyn for example, affinity match with the tactician affinity chosen at the beginning of the game? There was a question similar to this a while back. Will that code in the previous post work?

I don’t know much about this, but it would help if you linked the post you refer to.

It would be better to add to the preexisting topic than to make a new one, but here is it: Change a Units Affinity Based on Tactician Affinity?

The question is about if the code detailed there would be easy to implement and if it would still work if prior edits to the rom were already made.