> What about tongue length?
The length is also a function of tongue width/overall size. Two EI lams are stamped out of one rectangle, the two Is lie in the middle of the two Es. This is called scrapless or waste-free lamination because there is nothing left over. Another type is low waste lams with increased tongue length, but these aren't as widespread, and I think mostly for higher power appliations, bigger sizes.
There is also the
M lamination, which is square instead of the rectangular EI, so it gives more winding space. But they are not quite as common as EI and are/have been phased out of production for a large part. I think they don't exist in imperial sizes at all.