For example I have 2 local script now that will send signal to the server respectively to their combat style. Like HandCombat and SwordCombat.
If I want one player to have one Combat style and the other to have another, what can I do to separate them.
I can use local script to disable the other combat style but it wouldn't be secure and surely that's a bad solution.
I'd say you assign them numbers depending on the style you give to them. The scripts will have to validate the number to continue functioning. Not just numbers but on the player themselves that the script will check there must be a way to store those numbers inside the player themselves in their own model directory which is in workspace and username to that player and maybe use a string value or a model/part with a number on the name to show how it will be validated by letting the script look at the player and the model's name/string value with that number. Put it on a data store if you want it saved, oh and to apply this make a script responsible for giving out the numbers.
For example number 1 is fighting normally and number 2 is something number 3 is something something