You have to acknowledge that TES and Bannerlord are very different types of games. You don't have to test and balance weapons in Skyrim to see which ones are balanced for the sake of gameplay (more so for multiplayer). You don't have to code faction war and trade plans that have to adapt dynamically as time progresses with and without player impact in Skyrim. Etc. etc. Also, Bethesda had their game-making formula totally figured out between the releases of Morrowind and Oblivion, they know really well now how to get things done fast. For a lot of people working on Bannerlord, this is their first game with the company. For most of the rest, this is their second.