These are never 100% accurate and they will only show domains on 1 server and not a whole hosting companies servers. Also rememeber that if the numbers are higher then expected then it might not reflect accuratly the load on a server. I have seen comments around forums in the past where people say my host has 700 domains on 1 server... this is way too many. In reality it could be that 500 of those are parked and 100 of those are just static HTML pages. So it's hard to make a judgement on server loads with the above