Was asked by my dad, after seeing a commercial in which a Mariachi band is playing "Is there really a big guitar like that, or did they just make one up for the commercial?" I said there was, and had to look up the name. Told him it was a guitarron (even rolled the R's). Got me thinking, could someone play one unplugged and be able to keep up with other guitars?
People have been doing it for years but by the time you stack trumpets and violins on top, they kind of get lost in the mix, ending up as more as a rhythm instrument.
My dad said he thought there'd be guys that couldn't play it. Too small to wrap their arms around it. I said the backs are beveled so the proper playing position is to tilt the thing upward so you can reach the strings.
You might enjoy this thread while you're waiting for more replies: https://www.talkbass.com/threads/official-guitarron-club-and-discussion
I am not a guitarron player, but I have heard them a lot, they are loud ... way louder than any ABG you may play. Acoustically , they can keep up with 2 guitars a vihuela and a violin. But the technique is different than a bass guitar. For instance , you play 2 strings at the time, normally with you thumb and index finger.
You play them in octaves so you do have quite a bit of volume to them (think 2 bowed basses). All mariachi banda play them unamolified without issues (of course trumpets are way louder!)