If you are reconsidering those mountains, maybe you could add some more "tectonic" detail to that orogeny area. So, take the following if you like (if not, I had fun imagining it anyway, no worries).
- looking at you tectonic map, the plate on the right is a oceanic plate moving SW-ward, the one on the bottom is a partially oceanic plate with some significant land (maybe remnants of an old continent) at this end, moving northwards, and the plate on the right with the most of the land is mainly continental.
- now, to figure which goes under which you take into account plate density - generally speaking, old oceanic crust is denser, continental crust is "lighter"
- I would definitely make the part with the desert the less dense crust of the three, as that would fit my supposition that it is very old crust, this means the other two would sink under it
- this means the plateau would be in the deserted area (continent under continent generates plateaus - west USA or Tibet are the perfect examples)
- there would be significantly less land mass on the west plate (or, in other words, the mountain range gets shifted eastwards), as the oceanic crust sinks as it meets the continental crust.
- the shape of the triple junction would be basically given by the junction of the two continental plates, so figure the accurate border for these two and then add the oceanic one (there isn't really any location like this on Earth and I will try to explain why next)
- now, consider this is going on for a while (like millions of years, as always).. one of the continental plates is being pushed up, this means it will rise even further in the region, which in turns moves the border between that plate and the oceanic crust away from that triple point.
- over time I reckon this generates a "tongue" of up-moving plate breaking the triple point into two separate ridges, or at least, the tongue spreads as far as a point where two of the plates no longer collide head on but slide in opposite directions (transform faults)
I loved this bit of "what if", as I said, use it as you want it. I would get a bit of plasticine and try to figure it out. But feel free to ignore it