
Sometimes it can take a little time for the milk to come in after a C.Section BUT we've had quite a few births by this method, and in all cases, the puppies have been able to nurse from mum from the time they come home, if not when still with the vet after the surgery. Actually I kind-of like having mum basically 'out of it' immediately after coming home, so I can latch the puppies on without her really being that aware. The more they nurse, the more the stimuation should encourage lactation. And they do way better feeding from mum. Sectioned puppies can drop weight during the first 24 hours, but should pick up again.
I'd not be putting them onto solids at only 2 weeks, but perhaps that would depend on breed? For me, their digestive systems are way too immature to be able to cope with anything other than mum's milk, replacer milk or even goats milk. Hand rearing usually means bottling, or tube feeding every 2 hours right around the clock so depending on what, if anything they are taking from mum, I'd up the number of times you feed, UNLESS you can get them onto her, even at this later stage.
I guess if they are doing well otherwise, lively and not crying all the time, you'll just have to continue and hope they catch up eventually. Are you checking mum's teats to make sure she's not running to mastitis if they are not drawing off her milk?