I wholeheartedly agree with the venue size in relation to the system size – there’s no replacement for displacement. Even multiple driver arrays increase displacement. You need cone area for proper pressurization. Stroke helps, but doesn’t completely replace.
Yes, amp power is better being overabundant than just barely adequate. Over driving the speakers with a clean signal often allows them to run well, just keep an eye on overheating, whereas the nasty clipping of the underpowered amp not only sounds bad at lower volumes, it “can” stress the driver in non-standard ways that can cause overheating early.