No it won't. Quite a few bits of the EB architecture have change way too much to work with a RTW copy that has traces of older versions. In fact EB touches so many aspects of RTW now that many other mods; previously considered to be no pain at all running alongside EB (as long as you did not mind EB vegetation; or EB loading bars elsewhere) may now upset the workings of everything you have installed there.

Bottom line: if you had a copy of RTW 1.5 lignering somewhere on your PC which never ever saw a mod installed on top of it; you could copy that over to a new folder and install EB 1.0 on top of that new 1.5.