year old bump but i do not care
G91s were actually more versatile than what people believes:
G91s had bombing or strike assist computers
G91 R1B had the capability of carrying AS-30L saclos agms
Some G91s had an An/APA 90 indicator which warned the pilot of a friendly or foe aircraft inbound
there are also many rumors about the G91 R5 and R6 actually existing, this one in particular is from a russian magazine
"Finally, in 1964, FIAT manufacturer issued 25 vehicles, designated as G.91R/6. Landing gear were improved one more time and wider air brakes were installed. As export G.91R/3 for Germany, the most of these aircraft were fitted with 4 hardpoints instead of 2, which allowed to increase combat load twice. 2 additional hardpoints were developed during serial production. Also avionics was changed the same as for German aircraft. Fuel capacity was increased from 352 to 372 gallons. JATO allowed to reduced G.91R/6 take-off run to 100 m. Supplying of G.91R for Italian Air Force included only described above G.91R/1 and G.91R/6" source Авиаколлекция 10. 2015 Истребитель-Бомбардировщик Fiat G.91, p.11
and
source The Fiat G.91 by Giorgio Apostolo
For the G91 YS, imo its the better choice over any of the G91 Rs or the Y having 2 potent afterburners and sporting many improvements from the last generation, there are even conspiracies or rumors of its testbed having similar fancy improvements like a full fletched radar system including complete ballistic computers but no RWR