I promised lots of ideas, so heres more.
Due to the popularity of the roman sets, I would really suggest to release a second batch of that, and to keep it fresh, provide a different enemy than the Egyptians.
My suggestion would be Carthage.
Not an obvious choice, and likely not one young children would be that familiar with. But they can learn while playing, and they would be playing with some truly awe inspiring sets.
Lets start with the Carthaginian sets:
-Merchant ship.
A modified version of the Roman ship that has a cargo deck and various sacks of grain, several food objects, barrels and a chest filled with gold.
Included clickies: Merchant captain, two sailors and an archer.
-Armored war elephant.
This is the prize set of the Carthaginians, and one that would very likely appeal to children.
An African elephant, a larger version of the regular playmobil elephant comes with this set. It comes with a chain cloth over its back and a protective headpiece.
Attached to the metal cloth, on the back of the elephant is a wooden box for two archers to sit or stand on. In front of the box, there is a place for a rider to sit, with something to hold him into place, likely by his feet.
Included clickies: two Carthaginian archers and a black rider with a spear.
-Carthaginian Docks.
The largest set of the theme. It contains wooden docks with a wooden crane, a small light house that also functions as a store house, and a small fisherman's boat with a sail. Same size as the rowboat that comes with the hammerhead shark, but somewhat different design that allows for a sail.
Included items are various barrels, foods, buckets, fish and maybe a small chest.
Docks are large enough for the tradeship to be docked there, the set would be designed to work perfectly with it.
Included clickies: fisherman, dockworker, One archer and one spearman.
Stone wall.
A sturdy stone wall with a tower and various soldiers and a general, which could be assumed to be Hannibal.
-Scouts.
Two armed horsemen, a small set.
Moving on to the second batch of Roman sets:
-House.
A medium set with just a simple house and a Roman family. It would appear like a somewhat rich house, maybe a little villa since that would be the roman style kids would be familiar with.
-Roman legion.
A larger than usual army builder set, and I think this could really sell quite well for kids as well as collectors.
Included clickies: one centurion on horseback, a standardbearer with a horn, and eight legionaire clickies who all look different due to hairstyles, one having stubbles, some having brown hair, etc.
-Fountain.
A small set consisting out of a fountain to be put on a town square, a female clicky in a toga with an amphora and a child, and a Legionaire.
-Imperial palace.
A large set, containing a palace that has a throne room, bedroom, kitchen and a storage room.
Furniture includes a cookpot with a fireplace, a table with two benches, a fancy stool on raised steps in the throneroom, a luxurious bed for the bedroom, several small tables, statues and potted plants, various foods and of course a treasure chest that can be put in a secret hiding place.
Included clickies: Emperor, two praetorian guards, messenger/herald, servant woman, noblewoman. (could be used as visitor, advisor or empress.)
-Watchtower.
A roman watchtower with a ballista next to it, along with two archers and a centurion.
-reissued roman warship.
Same set as there used to be, maybe slightly renewed to have a counterbalance against the Carthaginian ship.