Actually, I believe each side gets up to 2 concussion subs and the other also then gets 2 additional subs to match that too.Will they keep the rule to allow up to two concussion subs too, so potentially 7 changes per team?
Current rules work fine, no need to change in my view
So technically you could have up to 9 changes per team (5 + 2 concussion subs + 2 subs to match the other teams 2 concussion subs).
If a game goes to extra time (so in the cup for instance) you also get a further sub in some competitions so in those cases each team could theoretically make 10 subs each meaning that you could end the game with 20 different outfield players to what the game started with.