Vaenyr
Ancient Mariner
I didn't say anything about "equally". One could argue about degrees of "gimmickness"How are they equally gimmick bands?
Maiden have always put effort into their visual identity. Their logos, the artwork, Eddie, the theatrical props in their live shows, and so on. We are talking about a band that has a dude in stilts walking around the stage play-fighting with various band members. Or stuff like the stage turning into a giant tank on the AMOLAD tour. The inflatable Spitfire on LOTB. Even when they tried stripping down their sound and image in the early 90s we still had Eddie bust out of a giant coffin.
While there are a few albums here and there that are seen as weaker, I think we can all agree that Maiden haven't compromised the artistry of their sound for the most part. Like, yeah, Steve for example gets a lot of shit for the "2 minutes quiet intro/outro", but I think most would still agree that he's doing what he wants, that he genuinely believes that what he's writing and delivers deserves to be released and heard. That's why I think it would be fair to say Maiden use gimmicks or have a gimmick (Eddie and all the visual stuff), without saying "they are a gimmick band" and meaning that in a negative way.
I can't really judge Ghost's music, since I don't listen to them. They clearly have a visual gimmick that is obviously one of the reasons for their popularity. There also seems to be a mismatch of their visual identity and sound, since the latter seems to be much less heavy than what their looks would imply. What I find is annoying when people conflate "Ghost suck" and "they have a gimmick" into one opinion. No one needs to like them, I don't really care for them. But just because they have a marketable gimmick doesn't mean they suck for that reason. It's a leap in logic that I see quite often. Might seem like semantics or overanalyzing negative opinions, but personally I find it more interesting if people would be more precise with their criticisms. It's obviously a lot to ask for, but it's also far more enjoyable to engage with. Seeing how people approach certain topics and how they express their ideas can be pretty fascinating, at least to me.
TL;DR: They aren't equally gimmicky but both use recognizable gimmicks, which is not a negative thing to me.