MO o e has a hard answer because no one knows! There is too much uncertainty in leds and the makeup of these lights. Lights can use 1 watt, 3 watt, 5 watt, 10 watt leds etc.
I have a 300 watt hydrogrow light. Why do they call it a 30 watt light, because it has 100 3 watt leds. How much power does it pull st the wall? 190 watts.
If I base my measurements off of 300 watt, for my 2x2 area, I get 75 watts per. At 190, I get 47.5 watts per.
For the ease of simplicity, just use the wall draw. For a 5x5 I would try to have at least 875 at the wall spread amongst 2 or 3 lights.
Also need to look at the light spectrum. Good idea to get a light with more than just blue and red leds. Ir, uv, orange, and white help to fill out the spectrum. Find something with at least a claim of 9 spectrums.
I'm a newb. Take this with a grain of salt. Hope you find the right light/s for your build.