Intriguing idea... but the real question imo is: those extra models for 105 pts are really cheap, but do i need them? because i could spend those points elsewhere.
Hahaha, very true. That's why I haven't justified it yet for anything beyond fluff lists. Every point hike on the skink priest makes them more valuable, but every point hike anywhere else makes them potentially less viable. I think they already have a place right off the bat in small skirmish point games, where you just need many small units to cover objectives on the board, and Klaq Trok is a tiny king in that game size.
Beyond that, I think their only value is screening. The oldblood can do some damage, but not enough on a foot model to justify 105pt, even with the ambush (you also have to bring the priest along for the ambush, so if you don't want him there too, that's 225pts for an ambush/backfield objective grabber, blegh)
So to get down to the math section of our class, how many linear inches of the board do they cover to block movement, and how many square inches of the board do they screen against teleports and reinforcements.
I measured them against the knights since they cover the most of the board in both aspects (okay, I didn't check skink in²/pt coverage, but I'll add it in later if it is relevant).
Knights cover
21.8 linear inches of the board (2.362in base x5, plus 4 inches between the 5 models, plus 2.999 inches on either end for engagement range)
The Starblood Stalkers cover 23.55 linear inches (1in base x5, plus 4 inches between the 5 models, plus 2.99in engagement, 1in being the smallest model that can sneak through, 2.99in engagement to Klaq Trok, 1.575in base, and finally 2.99 inches on either end of the whole thing for engagement range)
Starblood Stalkers hold a decently broad, paper-thin stumbling block that has a large gap our bigger models and units can sneak through.
And now for in²
Knights cover 570.9in²
Starblood Stalkers cover 736in² (435.5in² Skinks+301.0in² Klaq Trok; we also get to split them up to cover different holes in our screens)
Soo, as far as a non-battleline screening unit goes, the baggage side of the Starblood Stalkers is actually about as good as it gets on paper. The key word here being non-battleline. They are not durable, they will never do a lot of damage, and they won't check off a battleline requirement, but now we have the math on the table too. So maybe in Koatl's Claw in a knight spam list?