Shachar As far as I know ninja cookie is one of the few people who is actively trying to become good at every mode, so they probably have the most map completions in the current state, which gives the most cosmetic xp (how rank is calculated). Probably some concer or defragger has the most top10s, as they have a lot of maps and a reletively small pool of competition currently. There are a lot of people who specialize in only one or a few modes and won't be interested in comparing against those who play everything, which is why gamemode specific leaderboards for all the stats you mentioned are planned. Eventually the questions you asked will be easily answered through ingame UI with more depth on the website.
