A 24g is to small, Lions are waste makers, overtime it is tough to keep up with water quality, sooooooooo for a short time YES, but in the long run NO. It only takes one time with water problems and you could easily loose this fish.
The Fu ManChu is tough to keep and hard to wean over, if you attempt one of these lions you really need to have the LFS hold it for 7 - 10 days before bringing it home, they just do not ship well......
The Antennata needs around a 55 gallon tank, there is no way I would try one in a nano tank.......
Is it ok to put 3 dwarf lions in the same tank?
Not in a 24 gallon, otherwise yes, but it would have to be 1 male and 2 females, I would recommend around a 90 gallon for this mix.......
Kaye