I think everything should be in the player. Your account should keep track of which Tags you wore most, Even after you leave the guild. I have a firm belief that the statistics page should be much longer, much like the ideas thallen once posted about stats.
Player account should record the amount of times you hit the flag that season, how much time you spent on each individual tag that season, how many PKs BKs gralats and spars you had that season.
This way guild leaders can check their seasonal BKs, guild tag time, and amount of times they hit the flag to find the best players in their guild