"I guess even if it didn't succeed I could say i didn't succeed first "

Hold that thought.

No wanna throw cold water on yer fire here.
But, that can happen when hot air gets out over thin ice.

You've got 2 worries here.

1st. 200 milliwatt won't grow squat.
Don't matter how you spread it, diffuse it, or diffract it, you will need a LOT of diodes. Hundreds, in fact. (200mw X 200 = 40W. minimum.)
Then there's bandwidth.
LEDs are a much wider bandwidth than laser diodes.

We can get good results from cheap red leds at a 620 nm. wavelength because the light frequency is a curve in ordinary leds.
Output is centered at 620 but still has useful energy from 580 to 660 on the slopes of the curve.

Laser diodes have very little "spread" !
What you see, is what you get.
420 nm laser diode will have almost zero output at 460nm
It seems powerful and intense because it is coherent, almost a single frequency, and thus can be focused to an extremely fine point.

What you need to succeed is the proper frequencies of light with enough photons per sqft to build a big bush.
Bottom line, I doubt that it's a viable plan.

That said, please, do it anyway.
"Not succeeding first" is valuable information for the rest of us.

Half the fun is:weedpoke::weedpoke: anyway, ya?

Aloha
Weezard