Exactly right, KS.
There is however, one twist regarding the shape of the head. It did originate when an engraver confused a coin with worn-out headgear for a coin with a taller head, but the head shrunk to somewhat realistic proportions, then <i>was deliberately elongated, then curved </i> then returned back to more reasonable proportions. The best and most unambiguous evolutionary marker is the degradation of the attendants from a stick figure wearing a herringbone dress into an ordered pile of dots sitting atop two parallel lines.
It is tempting to call this one (1.1.2 Coin 5) the progenitor of my avatar...

But that evolutionary tree ends there. There are no subsequent coins; and the only two I have ever owned were even die matches to each other!
Instead, the gap is closed thus:
1) Stick figure attendant with "Mr potato head" portrait
1.2.1

2) Head becomes a bit more realistic, attendants legs disappear, lower torso becomes a blob with remnants of skirt hem
1.2.2

3) Engravers decide to add a line through the eye dot; brow becomes more prominent, lower part of torso either thins into a line, or disappears and is replaced by a remnant of the hem
1.2.4

4) Head suddenly elongated and curves backward, but the chin is still detached and the nostril and lips are still dots (this is a rare type, Mitchiner 421; not in Deyell or Maheshwari)
1.2.5

The above coin, or one like it, served as the prototype for the rajput king Chittaraja, fl. 1024 AD.
5) Engravers suddenly decide to attach the chin; the nostril becomes a crescent, and the lips become lips, beginning series 1.3

Important to note that the overwhelmingly vast majority of these specimens studied by Maheshwari were from a "pinjar hoard", found in central India and well away from Gujarat.
From there, the head becomes taller, then curves back sharply for the duration of 1.3

That's what gets me--the depiction of the "cone head" portrait comes in a period of careful, deliberate engraving and technological advancement to resolve the striking issues that plagued series 1.1 and 1.2. I do not buy that the elongated head could have been an accident. Maybe a hat, maybe head binding, maybe some cultural something or other that I don't understand...
Anyway, the evolution continues on to series 1.4 (the "Gadhaiya proper" if you will) and the chin again becomes detached, and the head almost instantly shrinks back down:
