As everyone here probably knows, Reimu cooked up Spell Card rules between MS and ESoD. That's why in part creating actual tier lists are difficult, since spell card battles aren't reflective of everyone's true power (particularly for people like Meiling).
What about PC-98 danmaku battles then? For example, would Reimu, Marisa, Yuka, and Mima be a higher on the 'how much ass I could kick if I actually wanted to kill you?' scale than say, Shinki? Or could Shinki pretty much stomp them into the ground if they fought to the death.
Because I've watched Mima's good ending on Youtube, and her ending could mostly be condensed to 'sheesh, she's pretty weak for a god, what's stopping me or Reimu from becoming a god if they're just that powerful?'.