By line source (instead of line array) do you mean you'll have a line of the M-130X drivers and one Neo 3 or 8 PDR? The X version driver should work really well in open baffle array. Having a decent low end will really set you apart from your competition. Cudos if true.
An array can mean a line of anything. A line of woofers and a tweeter can be an array. But a line source suggest line source propagation across the full audio spectrum. This means a line of woofers and tweeters.
What I have on the drawing board will be an open baffle line source capable of hitting a -3db down point in the teens.
How will you implement the second M-130?
The front M-130 will play up to the range of the tweeter. The second woofer will be in series with the first woofer but use a series network allowing it to cover the lower ranges only and relieving the first woofer of half of its low frequency duty and thus lower distortion levels to the mid.
I already started cutting the wood.

It will be killer good.