How to avoid the guest list conflict?!?!?!?!

If your parents are paying they control the guest list.

View Quoted Comment That’s my views on it but the fiancé keeps saying I need to stand up to my dad because this is our wedding.

Regardless of who's inviting them, guests shouldn't be invited based on the quality of the gift they may bring...
Have you told your dad that you would rather have your friends come?

View Quoted Comment I have and he said we would talk about it but he’s so stuck on “well we went to their kids weddings” and keeping tradition.

Can you invite both?

I think a fair compromise, especially since they are paying, is to agree on a guest count that each gets to invite. You'll have to negotiate the specifics of course, but if you are inviting 100, say that you and FH will pick 60 guests, and each set of parents gets 20. Or 50/25/25. Or 10/45/45. Or whatever. Make sure that if your parents get to invite, his do as well. It's only fair.

Tell your dad it's SUPER rude to invite people based on the gift size. My cousin invited me to her wedding in FL (I'm in OH) solely for the gift. I knew this when she reached out to make sure I had her current address to send them a gift.

They got no gift.

It's your wedding do what you want to do if you haven't seen them or even really talk to them then why would you want them there figure out the rest of your guest list and then maybe if you have room you can add them on but your dad should also be considerate that it's not his day it's you or your fiance's day

If they are paying for the majority, you should really just let them invite who they request. But I would also tell him that you want to invite your friends too. That may mean that you might need to pay for them to come though. Just have a good chat with him and explain your wants and concerns with inviting guests just because they "may" give you a good gift.

Those who pay get to choose and make decisions