It's more of a science/engineering communication effort, because there's a lot of unreasonable priors out there.
edit: also the 6.6GW of 'other' the current model uses, is the current actual gas plant size, not an amount that they predict as optimal or desirable. Similar with the Hydro, they used the current capacity, even though some are being built right now.
I may be mixing up his comment about limiting the Hydro to the current max output rate.
But, I believe they chose the levels on solar and wind to aim for, precisely because they knew 'other' would come in around this level, because it would be a poor demonstration of the viability of renewables otherwise. But they were at the mercy of the unpredictable weather and demand, so couldn't control it exactly, just much better than many people would assume.
https://www.wartsila.com/energy/towards-100-renewable-energy...
It's more of a science/engineering communication effort, because there's a lot of unreasonable priors out there.
edit: also the 6.6GW of 'other' the current model uses, is the current actual gas plant size, not an amount that they predict as optimal or desirable. Similar with the Hydro, they used the current capacity, even though some are being built right now.