A very good objection and a very good concluding sentence at the end.
Personally, I see Starlight Glimmer as being as naturally powerful as Twilight became through strenuous study. And this is where the plot armor kicks in. Never would a story, no matter who wrote it, be so satisfying that the talented surpasses the hard-studied. That’s something people instinctively dislike. For such a reason Achilles had to die. I mean, what significance would the fall of Troy have had if all the great ones didn’t die in the end? Except the smart ones. It’s the way man tells stories. In another universe, Starlight might have wiped the floor with Twilight. (grin)
But here’s my personal opinion: I like it and I like it VERY much when the supposedly bad guys turn good later. Not in an unbearable way. Not a complete 180° character twist. That’s why I think Starlight was actually handled very well over the course of the show. She was the pony that was missing. Not the seventh ranger. But a unicorn that needed to find her place in the world, learn to see her own flaws, and learn to manage her powers.
And I thought it was actually quite good that the duel with Chrysalis had ultimately led to her defeat. Not because she was incapable. Okay, you could talk about the go away from explosion move now, but hey, I thought it was cool. Very cool, in fact. It was a deserving scene. But since Chrysi was poweruped in the scene anyway, I was able to put up with everything that followed very well. :-)
My opinion remains: Starlight had the size, the power, and the personality to simply be stronger in combat than the Mane 6. But that’s not to throw a shade here. Spike was always the seventh ranger for me. Starlight, to me, was just always a size in the show that I never would have expected before. I’m very grateful to have been able to experience it. Starlight best pony. Change my mind. Especially in the constellation Starlight/Trixie and Starlight/Sunburst. ;-D
Should G5 develop as I hope, we will get to see at least one more big Starlight reference. And should that happen, I will throw myself on the floor in front of it and worship it ;-)