The only way I can see to have a less siege oriented gameplay is to have larger provinces, like BI. RTR went the other way - having more provinces than vanilla. To me, that's a downside of RTR (which I generally love) and makes it unnecessarily slow and at times tedious. I don't know what EB is doing - I suspect it may have a bigger map and so more provinces, but whether there provinces are smaller, I don't know.

I don't have a big problem with sieges per se - although I prefer field battles. It's just the AI seems much weaker at sieges (attacking and defending) than at field battles, so they are much less satisfying. I don't suppose EB can do much to improve on that, although some tweaks like making battering rams less flammable, might help.