Ranked mode would be cool, a mode that randomly put you in 8v8 as long as it only set up one map, so did 4 rounds each way then side swap like in competitive matches. However, I don't think a player ranking system which literally goes from say 1 - 100 would work. You see, giving a way to climb this through playing the ranked mode will not mean that the best player will be 1st, and the next best 2nd etc. It will mean that the most successful public 8v8 players will reach this. The people that play the mode the most will reach the highest ranks and not those that are actually the best. Perhaps an official TaleWorlds list that ranked competitive players accurately would be fine, however as it stands everyone has a different opinion of each player and they rank them according to how they think it should be - regardless, even if there was an official list made by TW, many would still not agree with it and would instead stick to their own opinions on skill.
Ultimately I'd like to see a public 8v8 mode that lasts for one map with 4 rounds each way then swap, as this would be a more accurate practice than just playing on IG as is now the case; however I would not like to see this mode used to rank players.