Can I just check if There is a way to obtain versions from the past?
Such as 1.5.4 or 1.5.3?

If I am not wrong, steam lets you do that for banner lord by going into properties, but I cant find the backup patches for GOG.

If you are using GOG Galaxy you can rollback to a previous update, but why you want to go back to those versions? The latest is incredible stable, I haven't experience any problems.

Hello. Normally people would like to rollback because of modding. M&B is a classic for gaming now and so many mods doesn't work with newer versions, unfortunally, specially those which use WSE (Warband Script Extender). As you probably know, M&B was a thing years before GOG and maybe even Steam, so you might find old Setups laying around TaleWords forums, specially preserved for Modding, if that's your intention. Try your luck there mate, you may find what you need!

Hope it helps, good luck!