I'm entirely with you on Matteo da Perugia... I seem to remember there is a nice piece of his called "Aquila altera" ("An eagle, from on high..."), although it might be Jacapo da Bologna or one of the others of that lot?
I think the lines aren't firmly drawn between instrumental and vocal music throughout that period, though
There is no rigid instrumentation designated for any of it, with a few examples where the circumstances of some particular performance are known (for example, how the fiddlers performed variations on "Kalenda Maya" - which is a supposedly vocal work).
De Vitry's music is remarkable, but somehow he hasn't enjoyed the posthumous prestige accorded to Machaut. Landini is also overshadowed by Machaut... I fear it's all to do with that "Ladybird Book Of The Great Composers" attitude of box-ticking "the greats"
And if I might be allowed a prejudice, I think part of it also stems from how much religious music composers produced... writers of sacred music have traditionally been more generously treated in text-books than secular composers.