Do you honestly believe that fusion power plants smaller than ITER (500MW thermal) could ever be economically viable, or are you just playing devils advocate?

Because your chart cements my point: Power produced by coal plants smaller than ITER (<500MW thermal output, or <250MW electrical power in your chart) is negligible because building those makes evidently no sense economically (almost all installed capacity is in big plants).

And thats with coal where building smaller actually reduces operating cost from fuel (unlike fusion) plus needs no vacuum chamber, cryocooling or dealing with neutron activation...

I'm saying ARC is "big enough to supply a generic steam turbine setup with heat," since you pointed out so strenuously that that's what they MUST do.

Getting D-T fusion competitive will be a challenge for everyone, but SPARC/ARC has an obvious advantage over ITER/DEMO by having way, way lower capital costs.