Production capacities, you mean? Of course, if you buy American systems instead, you don't have any reason to scale up your production capacities. As for interception capacities, Europe has two systems, one of which is 100% European. fr.wikipedia.org/wiki/Syst%C3...
Ukraine doesnt have the luxury to wait until we got our production levels on where we need to have them.
Like I said, so one more time, not the same capability. For instance patriot has a 120mile range to samp/t's 90. Samp/t is a nice system, with a nice radar, but it does not provide the same coverage. Ukraine already has Patriot systems and needs more missiles, currently only available from the US.