Let’s call the leader/civ mix and match mechanic what it is
It’s a completely transparent attempt to make it harder for Zigzagzigal to make Steam Workshop guides. Everybody knows that Zigzagzigal’s Steam Workshop guides are critical for new players to civilization, or existing players looking at a new civ, and forcing mix and match leaders/civs makes it difficult to create generalized guides as the playstyle can vary wildly depending on the combo of leader and civ. After all, each leader interacts with different civs in different ways. Zigzagzigal already had a tough job writing guides for multiple leaders per civ - and now? The job has become mountainous.
Why is this change targeted directly at Zigzagzigal, you may ask? Well, clearly, if you have to ask, you just don’t understand.
Nevertheless, I eagerly await Zigzagzigal’s civ guides as I am sure they will deliver high quality introductions to civs as usual.