The technologies required for Altay weren't ready when it was designed. For example Akkor. Even if we managed to make that tank in the planned time it wouldn't be fully functional as was expected. During the long-delayed time, the not only engine was delaying also armor had problems because it was designed to use French armor (looks like so many important parts were EU originated). I don't know what is the situation in Akkor but given it was in the final stage of development last year, I am guessing it is pretty much ready.
BMC power group will need more time, that's sure. Otherwise, we wouldn't need a Korean power group for a transition period. We need to keep in mind that even USA didn't have an alternative engine for MTU back then. After the last deal with Korea, I think our engine might get into the production phase faster if there are technology exchanges during the talks. We were supposed to provide them some part to avoid the German veto for the Korean power group sale. I hope this was really a lesson for our arms industry not to trust Germany and France again. Also, a similar situation is the same with other countries, I saw a lot of comments swearing not to buy arms from Germany again from many different people (Spanish, Polish, etc).
Also, can anyone explain to me, what is the purpose of an electric engine in these tanks? It is impossible to add enough battery to run the main battle tank. 2 ton Tesla Model S has a half-ton battery and Altay is 65 tons. It must be a diesel generator plus an electric engine to run it but I don't understand the advantage of this kind of power pack on a regular internal combustion engine. Also, it requires huge design changes and I don't think we have a generator or engine capable of such a purpose. And I am hoping they don't plan to buy it from Siemens.