The rules for this give us three points to consider:
1) Total of 60 Silhouette of craft can be carried.
2) No single craft can exceed (carrier's Silhouette - 2).
3) Us GM discretion on what can fit.
OK. That last one is the important bit, especially when looking at carrying Silhouette 5 ships. Is it reasonable for Silhouette 7+ ships to carry any Silhouette 5 ships? I can't imagine an Escort Carrier or Bulk Cruiser conveying Corellian Corvettes, Marauder Corvettes, DP20 Gunships or the like. Maybe one or two, but twelve is really out of the question even for a Star Destroyer.
Overall, I'm really surprised that this component allows anything larger than Silhouette 4 to be carried at all, especially as some Sil 5 craft carry fighters of their own and you could end up with a "nesting doll" effect (worst case I can think of is that Sil 8 supercarrier from Stay on Target with its 144 fighters and 10 sil 6 Nebulon-B figates in its RHB, each of those with 24 fighters and a RHB with five Sil 4 gunships--obviously violating the third point but following points 1 & 2).
Edited by HappyDaze