A familiar discussion. I understand the logic. Glad you are thinking along, it is most appreciated.
However, if you want to play a tournament server, play Quantum (quarterly resets, prizes for Quantum and Main, circulating themes and -now- a story arc) or make a compelling case why Chaos should be restored (yearly resets).
Main will not have tournaments other than the ones you organise amongst yourselves (i.e. raiding competitions, massing competitions, races to the next covert level or MS/UP milestone, or whatever your vast imaginations can certainly conjure). If you're thinking about more team-play, between alliances one could consider the Bloodwar a tournament.
The argument that "You would use your own Main account" is moot given the extravagant measures tournaments on Ascended required in the area of 'leveling the playing field', essentially stripping accounts bare of their uniqueness.

Along a similar vein, I have mentioned achievements, the (fair) development of which remains a challenge given the lengthy history of accounts currently in play.
So in summary, understandable suggestion, but there are already several options to the same effect at your disposal, and the benefits can not compare to the cost.