Predator doesn't seem to have the manual dexterity required for advanced species

That is your right to see things that way, of course. However, consider that the Predator culture is depicted as being older than ours. They have had centuries to develop their technologies to deal with their own physical abilities; as have we. We may see things as "you must have X to get Y" but they can easily see it as "We don't have X, but we have W and with that we can get to Z which will let us develop Y." Of course, they wouldn't think of it in that way, since they wouldn't conceive as X being necessary. Intelligent minds will work in their own way and develop whatever they need to accomplish their goals.

Humans have done this too. Most of the processes we use to build circuit chips and similar items could not be done with simple human hands. We developed other machines to build them. We couldn't do micro surgeries with just our hands and a knife; special tools, magnifiers, and other devices were developed to allow the delicate manipulation of human flesh needed to effect the repairs the microsurgeon achieves.

Keep in mind that geek Predators wouldn't be like human geeks. An easy analogy from fiction would be Star Trek. Klingons have been portrayed as a warrior culture, and for most of the various series and movies those are the only representatives we see. But a society could not work with just warriors. You need farmers, ranchers, laborers, lawyers, scientists, and technicians. Star Trek realized this, eventually, and we have seen Klingon lawyers (in DS9 and Enterprise) and commentary that the rise of the warrior is a relatively recent development among the species (recent being several centuries; but compared to a history of millennia, recent.)

Given the physiology of Predators we see, a geek Predator could probably take a MMA human apart and still be a geek.

Author of the Sodality Universe
The Road from Antioch
In the Markets of Tyre
Flight to Lystra
The Theater at Ephesus
The Council on Jerusalem (coming 2023)