Oh my, what a discussion
As one of the two owners of RetroCollect let me quickly add my two cents

1) The question of whether to ask here or right on RC
The OP has every right in the world to ask for feedback wherever he wants, I don't see why you need to critisize him for that

I want to add though that we're always open for feedback and everyone who's asked similar questions so far has gotten a friendly reply explaining things. If it turns out that a rarity is off, we will happily change it.
2) the actual question, are these rare?
The general rule on RetroCollect is that the rarity ratings refer to "complete in box" copies of a game. As such, games that are dirt common due to their pack-in nature can have surprisingly high rarity ratings. Examples include the NES 3in1 cart classified as extremely rare, our highest rating, due to a Spain and Austria/Switzerland only boxed release. Or the ones you brought up

This also means that cardboard packaged games tend to have a higher average rarity than others, resulting in the Nintendo systems having higher average rarities than the Sega ones. Keep in mind that finding a cart can be a lot easier than finding a boxed game, even for games not released as pack-ins. As a rule of thumb, the higher the percentage of toddlers among potential owners, the lower the ratio of boxed versus lose copies. E.g. a Barbie, Thomas the Tank Engine or Mary-Kate and Ashley game on a Nintendo platform tends to be harder to find complete, especially in good condition, than a similarly successful more mature title.