It appears the starting pikemen have remained, and are rather useful as a cav deterrent due to their morale effect.
ER wasn't the mod I had in mind when I eventually picked up E:TW last year, but it turned out to be the one I ended up playing most, and version 4 is proving the best one so far by a large margin.
Thank you for all the effort that has gone into it, it's greatly appreciated.
There's still the underlying problem that the 18th century is a singularly poor setting for "total war" and attempts to conquer the entire map, and any attempt at realism will run into issues because of that eventually, but the land battles in particular are so great that it's easy to put up with that.
I've been playing a Swedish campaign, and the one odd thing I've noticed so far is that Russia is attacking me with a lot of provincial infantry, despite their armies being recruited in their starting territories.
Other nations field regular line infantry as I'd expect, and I'm actually looking forward a lot to the inevitable clash with Prussia that's going to happen soon.