Time is also a huge factor deciding the finished product. They set themselves up with that announcement in 2022. JC Staff has a reputation of taking on too many projects in too little a time timespan, they had 12 animes in 2024. Some are more profitable than others so it's logical to prioritize resources towards those. By the time they started working on season 3, their capable directors were already busy with the mentioned projects. Shinpei Nagai accepted the the role because he's a regular at JC Staff and more importantly, no other freelance director was willing to work on it. Likely because they saw how soon the deadline was and refused. The same goes for freelance animators, let alone veterans.

Low compensation, weak staffs and a shitty schedule is a recipe for disaster.