The strikes are fairly laborious, yes, at least with the weapons they’ve given so far. “Shielding” and parrying are different buttons, too, and it’s got a Sekiro-style tell when it’s something you can’t parry. Parry windows seem short, but there’s an additional reason to parry because counter-strikes (also a short window) heal as well as do additional damage. It’s definitely not Bloodborne/DS3 fast.
One interesting thing is that heavy blows from the enemy when you’re near death seem to have a chance to blast you right out of your shell. You can keep fighting, but if you get back into it it seems like it heals you for a significant amount.