im not sure if its normal, i would keep a close eye on it. my son was a bit like it when he was small, hes now 7. he would line up his clothes, would only get in the bath if there was the right amount of toys in the bath, all his cars had to be kept in lines of 6 ( same number of bath toys) also his food had to be put on his plate so nothing was touching anything else or he would not eat! he also had a thing about touching some types of food and didnt like getting dirt on his hands, he spent lots of time washing them.
he also wouldnt get his shoes dirty would not jump in puddles and would freek out if he did yet dirty. i tried not to make a big deal of it if he did freek out i just tried to let him see that it is ok and nothing bad would happen to him if he did get dirty. all this started when he was about 18 mths old and he is still a bit funny about some things like puddles!! but i am please to say that as a rule he is a very normal grubby boy, its a real fight to get him in the bath most nights!!!!! try not to worry too much keep a close eye and dont let it get to out of hand without making a big deal.