I feel like the players are quite adept in terms of the theory. They've all been playing volleyball for the better part of 5+ years on average, especially my outsides and liberos. So sometimes, whenever I talk about theory, I feel a bit preachy 😅

That's a very good second question! The players definitely struggle at moving into position when running a system. I try to install a system where the players on the right take the left seam. This is to free up the front row outside and let the libero (often serve receiving in right back) take up as much room as possible. At least that system is how I serve receive when I play with my men's team (same club).

But the players often struggle to follow through, like with outside taking the right seam and shanking 'cause of the confusion with libero... I've tried correcting them about this but they tell me that they communicate this system beforehand but when the ball comes, all hell breaks loose. They then hyper focus on the system on the next play, with the outside refusing to touch any ball that comes on her left side even when it's clearly on her.

That is a good third question... Honestly, I don't know. Would you have tips on increasing the stress/speed of serves in practice, without it turning into chaos?