Pimento to me is very, very different from nutmeg. Pimento will vary with variety. The CO2 is very different from the EO, for example. I have no memory of a clover note in the varieties I've used, but smell memory is flawed, and I'm not sure what you mean by clover note, to be honest. I remember the smell of clover from my front yard as a kid a little bit. Maybe you could give it another chance?
I can remember disliking some blue chamoniles I've tried, and I had to sample several chamomiles to find one with the smooth, nonintrusive qualities I wanted. Usually, the blue varieties have been more "assertive" in a blend.
Good idea to use wintergreen, which often contains a high percentage of methyl salicilate. Try it and see. I think it's a generally useful note, in any case, so you might be pleasantly surprised? There's a menthol note in there too, and an anise note.