this link argument is ridiculous. no character should be represented by itself three times, even if it's three different iterations. they're all link.
sure, a franchise can get bloated (looking at you, pokemon), but a single character? you can't be serious.
past that, you then consider which of the three can stay. two is a fair number because people can look at link as a coin. you can consider one side of the LoZ iterations on one end, and the other side the back end. so, 2 stay, 1 goes.
after that, you must consider which are the best representations. so, we have the mainstay of the series, and we've got two deviants here. link must be available, because he's been in each smash prior as well as the main iteration for the less stylistic approach to the LoZ games.
it's between TL and YL now. YL was in melee, but TL was in brawl. since mechanically YL stays (mostly), it's about aesthetics now. who's the better representative, the previously known character with his moveset, or the newer character with his predecessor's? i'm on the end of TL. explaination: he embodies the other side of the LoZ franchise coin. YL may have seniority, but he's just not a representative of the games now. this may be a throwback to melee, but it's in this timeframe. 2.0 means the sequel of melee as of today, not as of yesterday.