Looking for advice on having competing Luck and Agility stats when determining Chance to Hit in my Homebrew System

Hi all! Just discovered this subreddit as I was googling around for people discussing the topic, and I haven't quite been able to find conversation around this specific question on "chance to hit" in combat. I am currently making a homebrew system based on the 1997 JRPG Wild Arms (and its sequels), involving a sort of "anime" take on the American wild west, as well as some really unique combat elements I wanted to try incorporating into a TTRPG. I am taking lots of inspiration from other combat-focused systems such as Lancer, but when it comes to determining chance to hit I have had some difficulty making a decision on what would work best. Being able to hit with an attack is incredibly relevant to the system, but I want to leave room for people to put points into and specialize into dodging these attacks as well.

My current idea is to have dueling d20 rolls, the attacker and defender both rolling a d20, the attacker adds a Luck modifier and the defender adds an agility modifier. Afterwards, damage is rolled seperately. I like this method, although it feels like it could potentially be hard to balance around, since if I make the modifiers too weighted then a majority of attacks will be evaded, and if the modifiers are too weak, then characters putting points into agility instead of defense will feel their efforts wasted as they get hit with the brunt of attacks just like every other character. I should also add some context on the unique nature of the combat system I'm designing:

To give the briefest explanation, the way "spells" or "abilities" work in Wild Arms is that instead of an MP system, they use a "FP" system, or "Force Points." These are gained by dealing damage with a normal attack, receiving damage from any attack or ability, or dodging an incoming attack or ability. Once you have acquired a certain number of FP, let's say 50, you can use any skill that requires that amount or less FP without spending the points. Simply put, you do not spend FP to use abilities, you only have to reach the threshold of those points in order to use those abilities. Combat involves trying to make decisions around making many normal attacks in order to reach a high threshold for powerful abilities, or making use of low-threshold abilities instead during your turn, while slowly accumulating more when receiving or dodging damage.

I wanted to put that explainer in there to add context to why hitting with a normal attack is so important. If I have a strong ability that needs 80 FP (100 FP being the maximum), then I need to be able to make normal attacks to reach that threshold consistently, and missing an attack would mean an incredible set back in terms of what a player does on their turn, as well as their progress towards the cool abilities they want to use. I'm curious what you all think would be a good balance, where players can simultaneously not feel like their turn is wasted by missing a lot, but also so that characters who want to dodge attacks can feel useful in that way. Obviously this is not the whole context of the system works, but I'm happy to elaborate more if anyone has other questions about it. Thanks for your time and I would appreciate any advice or tips on how to balance this "chance to hit" mechanic.