I understand totally your concern. If he stirs every night you go in, perhaps can you try not to go in for 3 nights?? and see what difference it makes?
I have a theory (which has worked btw DS was 2). that when an LO has an EW, it is an indication of what the best time it is to put him to sleep in the pm. If he wakes at 5, put him to bed at 5pm.
What is your gut feeling? Too much nap? have you been shifting bt, nap time constantly due to inconsistent wake time? (I was doing that for a very long time.) DS suddenly slept 2h solid nap and slept 12h at night at 24months. So he got old enough to fit into whatever times I thought worked. If I was late by even 5 mins for his bt, I would get NW and/or EW!
I suggest you look at your EASY and figure out what you think is the first thing to try. Have you tried fixed nap time also? It might help, if not his sleep, your sanity!!