I believe 32 is the target number of escorts, and has been ever since the 1998 SDR. The fact that the government, through appalling management of the military, have allowed it to slip to around 16, is a fvcking disgrace. Don't judge by the current numbers.
Up until last week, the number of C1/Type 26 I had repeatedly heard was 12 (or rather, ''don't hope for more than 12''). So 10 is reasonable. Bear in mind that this is essentially a new capability, which will replace both the Type 42s (that the Type 45 hasn't due to numbers), and the Type 22s, with something very different. So we're replaceing 12+4 with 6+10. The Type 23's will effectively fill the C2 role until the new ships (C2/Type 27) start replaceing them as they decommission (we're talking mid-2020's at this point). It also gives you some idea of the size and capability if you think of them in terms of a roughly 1-for-1 (plus 3, as per current plans) replacement of the type 23. When you consider the 23's are being upgraded with CAMM, Artisan radar, 2087 sonar, etc... we're talking about a very capable replacement.
The C3 is the one that is a bit iffy in my mind, it's going to be one heck of a challenge trying to fit all those different capabilities of the OPVs/MCMs/Hydrographics etc on a single hull, even if it is modular.
At least now the RN is being given what it needs to both modernise and get the numbers up. And it only took an election to get the politicians to support...!