I have 10 5-star dragons, but they are not high rarity. Terra, flame, sea, flaming rock and volcano were just so easy to get in heroic races and so fast to recall and empower that it seemed silly to waste them. Same for Dark in alliance races. Pure was fast enough and easy when I was breeding for last few legends. Destiny, hard-headed and fuming were done with orbs won in alliance chests.
I have 3 4-star dragons, all Commons, from alliance chests and arenas warriors chests. My gorge dragon is currently empowering to 4 star, I purposely bred duplicates for this, have a few more to breed for the last star, and I only feed them to level 10 to get 40 orbs per recall.
I have 10 3-stars, up to Epic rarity, got from alliance chests, arenas warrior chests, event prizes (clarity and reason), and gummy from puzzle island breeding.
I'm working my sanctuary right now for supersonic. And my tree is doing gorge still but will start Kratus soon.
Aside from heroics, which I have 8 at level 40 for leagues, I use 10 legend and 2 epics from level 35 to 38 for arenas. And skip fight where I need to, or wait out the gem skip. Like Nynaeve, I am more a collector than a fighter, but I am ftp so rely on in-game food for leveling up.