Actually, SHA-2 algorithms are not that difficult to write for hardware, they are very FPGA/ASIC friendly. Any graduate student in Electrical/Electronics Engineering could whip one out in about 3 months or so, I did so back in 2009. The problem that you are going to run into is designing/optimizing for maximum efficiency, and doing so requires additional time and effort. And I believe that Cointerra is 10 times more qualified to do so than I am.
However, I do agree with you that tape-out was expected in September and that did not happen. Now, tape-out might happen towards the end of October, and if it does, there is no way the December delivery is going to happen. Cointerra is going to have about a 65 day window to complete everything and have the hardware at your door step. Not to mention that Quality Assurance (QA) by itself takes a long time for the type of hardware quality that they are aiming for. I would rather have them to be late than rush and lower their standards such as KnCMiner did. No, no, no, I would rather they delay by a couple of months and deliver high quality products.
The problem I see with Cointerra is not with their Engineering skills, they have the best team for designing Bitcoin mining hardware - their problem is KnCMiner. Why, because a lot of people would rather buy a higher priced miner today, than a lower priced one 3 months from now. They also want the ability to use Credit Cards, PayPal, and have refund options. KnCMiner has all of that going for them because the got in the market first and there was no real competition.
Cointerra started late and the pre-order well is running dry, the other manufactures who got in first drained it. They have to balance funding for research and development, and potential customer refund requests. So how do you deal with that without outright refusing refunds such as what Butterfly Labs and HashFast are doing? I do not know, but I believe this is their major problem. Refuse refunds, and you alienate a big pool of potential customers.
Please Conterra, just come out and say that you are going to be late for December delivery because you cannot rush perfection. Your team will gain more respect and bigger wallets down the road.
I never said SHA-2 algorithms are difficult to write.
I did say Cointerra has ZERO EXPERIENCE designing a new chip from scratch and that will cause them problems.
SHA-2 is the easy part. Managing the logic/power/heat of a giant chip with dozens of SHA2 cores is the hard part.
You have arrived at a contradiction:
1. Cointerra is a month late with their tape-out
2. Cointerra has "the best team for designing Bitcoin mining hardware"
Both of these statements cannot be true; one excludes the other.
You need to check your premises because one of them is demonstrably false.
Hint: it's not Number One. 
Now that Cointerra has botched their mock tape-out, it's time to stop assuming they are the ASIC Dream Team implied by their slick marketing and website.
Logic demands we judge Cointerra based on their demonstrated incompetence, not their fancy hagiographies/pedigrees/titles of nobility/etc.