yes, but these are rare circumstances from my point of view.
I deploy defensive regions with w75 - w80, while my offensive Divisions are combined always w38 - w40.
Might not be perfect, but works fine for me.
They aren't exactly rare, not only fighting across rivers can drop you to bridge fighting, having SF doctrine as the defender can drop you to tactical withdrawal phase, and SF doctrine is pretty common. Encirclement tactic doesn't need to be unlocked, just have its conditions met and its weight can even be boosted with officer traits. And then you can have mass charge and guerilla tactics from a mass mobilization doctrine that can also mess with available width as either attacker or defender. These are very real possibilities that can have dramatic effect on the outcomes of your battles.
I am not sure what you mean by having 75-80 width for defensive regions, telling me that by itself is practically meaningless. You should be having 80 to 120 width in every province you intend to defend, preferably in 20 wide chunks for 4-6 divisions. As the attacker, you have a lot more control over the available width by choosing to open flanks, or cancelling an attack and hit them again to re-roll your tactics if you didn't like them. That aside, there is hardly a penalty to the attacker if they lose a combat, while the defender gets all of their divisions kicked out of the province. Since the defender has little to no control over what the width of the combat is going to be, I would suggest leaning a bit more towards universality of width for your defensive templates than you would for your offensive templates, where you do have control.
And sure, X or Y might "work for you". But that doesn't stop something else from working in whatever way, better. I'm not going to become complacent and marry the first things I stumble across that "works". I'm going to put a bit of elbow grease into figuring out why that works, and what might work better.
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