Is changins Saving Throws proficiency unbalanced?

Ok, so, I'm asking for a very specific example, but this does serve as a general rule.

As we all know, there are two "types" of saves. The more common saves (DEX, CON, WIS) and the less common saves (INT, CHA, STR). Every class gets proficiency in one of each type. So, if i wanted to, would it be balanced to change a saving throw proficiency for other?

My case is an Arcana cleric. I feel like they should have INT save proficiency, so, I thought about changing the CHA proficiency for INT. Is this unbalanced? And, also, do you have any ideas for something you could do with this "system"? I always thought that fighters should be able to choose between DEX or CON for their save proficiency.

ty for reading <3