I'm in the middle of reading Brian Herbert's sequel to Chapterhouse, which describes the process of growing gholas as a traditional 9 month coming to term of a baby, without any accelerated growth afterward. And it's not a matter of lost Tleilaxu of the Scattering forgetting advances in cloning technology, considering Scytale, the last original Master, utilizes the same methods. Aside from the ability to birth one baby after another, the whole thing almost defeats the purpose of Axlotl tanks, as I thought the mutated "mounds of flesh" women would've been able to birth full grown men. Makes me wonder how closely they actually followed Frank's notes.
They didn't. Kevin J Anderson if he is unknown to you is a hack writer who churns out novels for licensed properties. He is well known for 1) dictating his works via tape while hiking and then having a secretary transcribe them and 2) being hated by almost anyone who has read his licensed material.
After he got ran out of several licensed properties including Star Wars, he set his eye on Dune and was able to convince Herbert's gullible son to have him expand on the original work. The discrepancies and mistakes are undoubtedly the result of laziness on their parts and sacrificing faithfulness to the original material for dramatic license.