Is a small silver shark ok for a community tank containing Guppies / Neons etc.

I was at a fish store a couple of days ago that had 2 tanks with silver sharks in. One was labled 'standard silver shark' the other 'small silver shark'
I thought at the time it was odd cos even I know they get HUGE ... but this query now begs the question "are lfs' selling sharks as small when there is no such thing" ...![]()
if it said 'small' and the fish were a foot long... id question it... of it said adult or xl and the fish was 5cm long then id be a bit annoyed.