Well I wouldnt consider playmobil to be that suitable for four year olds when you look at all the delicate items. I'd be too worried about them breaking it.
Some sets like a few figures, a car and such seem like a good start for that age, just not the smallest parts since at age four most kids would lack the dexterity to really place all those tiny cups and such on a shelf anyways.
But what baffles me the most is that they put age 10 as the maximum age for it, that could be at least age 12. They might be hurting their own sales with this a bit too, by limiting the age range like that. I'd say at age 10 they will start making more detailed stories with the clickies, learn to be more accurate with historic themes due to history lessons on school and all that.
