Mono Cartridge Stylus

It is not clear to me why you are confused.  Actually, I don't believe you are confused, rather it seems you have figured this out correctly.  Since the majority of your mono records are Microgroove the best stylus option for you is 0.7 mil. 

Got it. Well now I am going to open another aspect to the mono discussion that had me scratching my head for a long time.  That is what shape works best.  Miyajima makes a case for their wonderful sounding conical stylus.  I have a Zero.  Peter Lederman of SoundSmith makes a very compelling argument against conical and I have learned that they are in fact hard on records.  For old jazz I actually prefer a very lowly MM cartridge only available in the EU that has a Shibata stylus, it is the Ortofon 2M Mono SE.  But is is lousy for classical being too bright and edgy.  The Miyajima is easily the best for that, which is a dilemma.  I also have a VAS Nova, with an elliptical styllus and reasonably priced, a SoundSmith Hyperion with a line contact and pricey that are both good sounding for classical (but not as good as the Miyajima) and are easier on the records.  I have others, the accumulated detritus of a lifetime of seeking unobtainium.

Maybe we are, but I want to be clear.  A 0.7 mil stylus often sounds terrible on a pre-Microgroove record, and a 1.0 mil stylus might jump right out of the grooves of a Microgroove record.  This is why Miyajima and others make both and why collectors seeking best performance need both.  It is not correct that both stylli can trace all generations of mono records in all cases. Very demanding material requires proper matching.  

Any collector of mono records will probably wind up with a mix of microgroove and pre-microgroove records.  Miyajima has catered to this market for many years and makes stylii for both types of records.  If you are interested in collecting and playing these records you are going to have to make a decision about whether you want to be able to play both.  It depends on what you want to collect and listen to.  If you only want to collect reissues, then you only need microgroove capability and that will simplify your requirements.   

Miyajima is correct.