If we consider the design of early keris and other keris-like implements, as shown in 1000 year old monumental works, we can very clearly see that these weapons, at this time, did in fact have a separate gonjo.
http://www.kerisattosanaji.com/origin-of-the-keris
The manners in which a keris, or keris-like implement, was held when employed as a weapon dictates that the blade base needed to be sufficiently wide to cushion the hand and forefinger against impact. In many other weapons employed in a similar manner, but coming from other societies, this cushioning effect is achieved by the fitting of a separate guard to the blade.
The keris became an icon of its society of origin as time passed, and it achieved over time, the esoteric interpretations that it now carries.
In early Javanese literary works the keris is depicted as purely a weapon. This weapon function continued for hundreds of years, and still exists, alongside the many & various esoteric interpretations attached to the keris.
Some of these esoteric interpretations have existed for lengthy periods of time, other interpretations seem to arisen only very recently.