No, capturing something doesn't mean being able to replicate it.
What if WWI factions obtained data regarding(or captured) an F-22? Do you think they would have been able to build F-22s? No!
Not immediately, but given time they would (they'd have to figure out the fundamental stuff, like computing, metallurgy, engineering and physics...etc., before moving to the technicals - building machines, devices to build the little stuff to make the tiny components of the jet), the only question is how long would it take? If they somehow got their hands on an F-22 back during WW1, no doubt its completion would be at an earlier date than our current timeline. It just might take 30-40 years for them to do.
But we are talking about the GTVA here. So, let's see what they need to first replicate a LRed:
knowledge of the beam: wavelengths/frequencies to produce beam. Energy requirements & heat loss/efficiencies. Easy enough to study if you have a captured LRed-firing ship.
sufficiently powerful energy source: Shivans have high energy crystals (for example the stuff in those Shivan comm nodes, cause massive explosion on destruction). Fair to assume these can be used to power those beams (or capture Shivan reactors and take those apart), so the GTVA just needs to figure out how to produce their own (by analyzing atomic & molecular structures, behaviours under various conditions) or salvage Shivan debris/steal their cargo.
Strong heatsinks: This is fairly straight-forward, all Shivan beams are projected from red/black beam tips, the materials of which are easy to acquire from Shivan debris/wreckage. Again, analyze material composition and replicate (difficulty will vary depending on how complex the molecular compound is, rarity of material doesn't seem likely if the Shivans could have armadas of that size).
Do feel free to point out any weaknesses in my thinking, I need the exercise before I start university again this September
