I got a call from the preschool coordinator. Short story is they think we should wait until spring to give E. more time to learn English, adjust to his new home and catch up developmentally. I had many questions for her, and she happily answered them. We will re-screen E. in the spring if we are still having concerns. Meanwhile I may investigate other preschool options locally and speech therapy. At the very least, we'll keep going to playgroup, therapy, and play dates. We have been spending our days playing, reading, singing and doing what 3.5 year olds do best.
On a side note: I have had several professionals tell me that he is more like a 2 year old developmentally, and I agree. Aside from the fact he his talking more, he and S. are almost on the same emotional level. S. is 21 months old. (except E. is VERY tricky and sneaky, almost passive/aggressive) Sometimes they get along great, sometimes not! They often even wear the same size clothes and many times people ask if they are twins.