You should have quite a mixed bag. I have alot of 3,4, and 5 leafed 1 prongs as well as some 2 prongs. Believe it or not I also have some 3 prongs with 3 leaves on each prong, but the vast majority will be 1 prongs and small 2 prongs.
Well once you get an eye for spotting the leaves then its all good. Your eye will train quickly. I used to have trouble seeing it in patches or in the wild but now its easy peasy. The plants whether they are young or old single pronged or 4 just have that same basic look. Hey general thats pretty sweet to hear you have tiny 3 prongers! I was noticing that a smidge where I planted but figured it was pre-existing "seng". I still think the ones I have are but I guess I could always peek at the root and check the years to see.