The problem of the: lag, high ping, latency, skills that doesn't fire, ISN'T the size of groups, the out-of-party heals, the new skills etc.. The real problem is the big unique istance of cyrodiil.
In Imperial city you can make 20 players group with the most broken sets and skills, you can fight against 100 players at time without serious lag issues. What does it means? Istances are the key to the solution. Lot of players had this idea, lot of players have made lot of work in forums and reddit giving zenimax some ideas to use, but no one have been listened. Just re-work cyrodiil including more istances and you will fix the lag for ANYONE. Imperial city is the best pvp dlc you have ever done, lot of players are still playing it just for the fun to do some pvp without lag, where skills matters, where you can still heal that solo player being killed by 2 opponents, where you can still make big groups and do big combats against other guilds without having the issue of a lag spike. Listen to the community, we want only pvp without lag. Istances are the solution. Cyrodiil is too big, there are even areas that no one knows or goes to; but don't misunderstand me, i don't want a smaller cyrodiil, we Don't like the idea of hundreads of loading screens, we just want pvp to be without lag and lot of players thinks that istances are the solution.