I think there are some changes in the appearance of the coin that perhaps justify at least two subtypes:
1. Date in field: Obv: Armored bust of Philip right wearing thin collar, dividing date (if present). Reverse: Crowned quartered arms in ornate frame, the crown decorated with palm and olive branch. Crippa 13
Undated, 1579 - 1588
2. Date beneath bust: Obv: Armored bust of Philip right wearing thick ruffed collar, date beneath bust. Reverse: Crowned quartered arms in ornate frame. Crippa 14-17
1592-1594
I do not have Crippa, but from auction results, it looks like this is his classification system (#15-17 appear to be smaller variations).
If this is OK, I will go ahead.