Well if they follow what was recommended for S3C3 or whatever they called it (10 C1's, 8 C2's and 8+ C3's) for FSC then I do not see what the problem is, as we will have plenty of hulls in the water-32 at least.
But C3 was not intended as a first line fighting ship. From Richard Beedalls site - 2007.
... Cdr Brunton identified these as:
* a Force Anti-Submarine Warfare (ASW) Combatant (known as C1)
* a Stabilisation Combatant (C2)
* an Ocean-Capable Patrol Vessel (C3).
He said "... C3 would replace the capabilities of our existing mine warfare fleet but also offer additional capability for maritime security tasks."
...
C3 is currently envisaged as a vessel of approximately 2,000 tonnes displacement with a range of 7,000 nm for constabulary and minor war vessel tasks. Cdr Brunton said "We see this vessel being used for maritime security and interdiction operations. It would also have a large mission bay aft, reconfigurable for special forces, MCM or a Lynx helicopter.
A 2000 ton OPV, configurable for minesweeping, etc. Good for chasing fishing boats, drug smugglers & pirates, but not comparable to a frigate.
Also, now Type 45 has been cut to 6, what's the prospect of getting another 18 first line ships?