Interesting theory, although I don't think they would increase the size of the bay if the role of the Polaris stays the same. It is supposed to be for a recon fighter if I understand what they want the ship to do overall. It would be cool if you could put a Terrapin in there though, that seems like it would be the most useful thing you could put in there.I'm guessing. It's only a guess. They don't need to all fit at once anyway. They only need to refuel. However, it does seem if they'll fit, they'll make large jumps much, much more quickly. The benefit of using them as stealth recon spotters for the Polaris Torps is they will coast uncoupled at VERY high speed--325.
Scan area is a radius circle, so the area you can scan is quadratic (r^2) with scan radius, however; if you are scanning a region by drifting through it, the area you can scan over time is linear with radius, so it matters much less that the scan is short radius if the movement is very high. Looks like a plausible solution so far.
Current rumor is the Polaris bay is 29L x 21.5W x 8.95H. That's until the entire ship goes through the size creep from the new dimensioning of all the walls, etc. The ship could easily go from 155m to 180m and the bay would grow with it. If not, then it would only fit 4, but it only needs to grow just a little to fit 6 and that seems likely. Also, there is room to stack Razor's 3 high if there ever develops a way to do that. I would not be surpeised if 6 Razors and 6 X1 Force bikes will fit in the hangar, but we need to wait and see. Will likely be another 2 years.
Point is, I can imagine paying to keep 6 top-quality NPC pilots on tap for use with Vangaurds and Razors. If all the NPCs do is launch missiles from Harbingers, I think they will be able to manage, and if all they do is drift a sector to scan, that could work too. This keeps the real players available for the real thinking tasks.
As for the high coasting speed, that doesn't matter any more with the changes to the fought model in 3.5. You can get anything up to 1000 m/s, it's just a matter of how long it takes to get there.