>>10505603 Don't need the novels to be finished for another 26 episodes, srsly, they have enough material for 26 episodes of main story and another 13 episodes of fumoffu.
Have you read the novels or summaries of them?
They're not in a state where you could just make a 26 episode anime and then stop and wait and do another series later to finish it off.
Apart from one short story, all the novels following what has been covered by anime so far as serial in nature, and most of them end on cliffhangers.
They'll also be a royal bitch to anime because 1) zero comedic content, 2) they span a considerable amount of time (two minor timejumps) and 3) all the main cast are separated for a large portion of the story