Did some searching, after re-reading this entry. Searched the Internet, and found that Amazon.com has a lot of nice dino skeleton sets, for reasonable prices. Here is a set of 100 pieces, for $17.99 USD + shipping! That's only $0.18 USD per figure!…
I would paint them with Minwax Polyshades Urethane Stain, Royal Walnut color, base them, dress the base, and done. This will give them a, "just dug up," look. This is how I paint up all of my skeletons. They look fantastic, IMHO. The plastic is the proper color for this to work: light tan. The Minwax will darken them just enough, giving them a variable brown staining. In the recesses, it will pool, making them look just right.
As to how useful would they be for fantasy games, with Dragons?… Considering that Liches can live for centuries, or even millennia, I would say they are very useful. I had an RPG Lich foe, who spent centuries building up his skeletal army, right beneath a large city he wanted to destroy. Everything was going well, for centuries, until some pesky adventurers stumbled into his cavern housing most of his skeletal army! They forced his hand, such that he had to launch his attack, before he was ready. He feared they would alert the living priests, above, who would be dispatched to destroy his army!
We played out his attack on the city, using 2e's BattleSystem rules. It was a blast! I would have loved to have had dino skeletons in his army… Oh, well. It was fun, anyway. The Lich had constructed an artifact which would allow him to assume control of a single unit of undead, each turn. This effectively allowed him to use each unit as a land torpedo, firing them at his chosen enemy unit, but it meant that he still needed to rely upon intelligent undead commanders, such as vampires, to assist him in controlling his army. It was a lot of fun… Cheers!
