Personally i think that Ishinomori´s influence in the genre exists more in a writing level, he created stories that always had a high-end concept behind them and this really help to cement Tokusatsu as a proper genre and not just special effects escapism.
And really, many of the common tropes that we tend to associate with Tokusatsu were pretty much created by the man, from your secondary rider/sixth ranger/extra warrior (Riderman was basically the archetype) to your cool morally ambiguous badass villain (Hakaider).
Ishinomori certainly didn´t create the genre (the first henshin Hero, Gekko Kamen, appeared in 1958), but he certainly helped to define it and shape it into the Toku we know and love.