Shape-wise they do look like severus but it's odd that in a group you don't have any with the half-bars. I'm suspicious that they could be Inirida which are sometimes mistakenly sold as severus when they're juveniles. Both fish look really similar and have similar barring. It could also be that this seller got the fish from a source who separated out the "correctly barred" ones and sold them to someone else, and then wholesaled the misbarred ones.
Unfortunately you won't know until you grow them out a bit more, but body shape tells me it's severus or sp. Inirida.