That is a tricky question. If we had easily accessible PPFD amounts, it would be fairly straightforward. I used watts per square foot, which is an ugly metric, but it gets you in the ballpark.
Im lighting a 2x4 area with 24 2ft strips and the HLG 480h 24a. The strips themselves can be turned up very high, my driver maxes out at about 22amps of current or 530 watts, but the 24 strips can handle up to 28.8 amps of current (1.2 amps each) which would be over 700 watts.
I run it right now at 300 watts (12.5w for each 2 foot strip) or just below 40 watts per square foot, which I think between 30-40 watts per square foot is a good place to be.
If you are trying to lignt a 1.5 x 4 area, 40w per/sqf would be 240 watts and at 12.5w a strip that would be 19 strips. You could get away with as few as 12 2ft strips, or 6 4 ft strips but the more you have, the more light per watt is produced.
I hope that helps you on your journey!
