Sounds too good to be true, so it probably is. What's the catch?
The catch is that he's being a bit loose with his definition of "mining at the same time". Some of those coins support merged mining (UnitedScryptCoin, PesetaCoin, HunterCoin and OrgCoin, apparently) so these will mine concurrent, but you can't mine LTC at the same time as Doge/Cat/Pot/Digitalcoin and get payouts for all, you have to pick one.