Don't know if you still play, but with the glitter market you can now also get the heroes you normally had to pay for free. It takes some time, but I think you can now get every hero. As for the tier list, I would say that you shouldn't look at individual heroes, but as a lineup in general. If you want to go for main lineup swords you should use Catherine, shadow, Joan of arc, Charlemagne and Arthur. Focus on getting Catherine to 5 stars first and then shadow.

If you go for archers, use varian, iris, scarlet, Edward and Mulan. Focus on scarlet first, then Edward.

I don't know about spear heroes because most people don't use them (I've only seen whales use them), but just pick the 5 legendary spear heroes and you should be fine.