You're not wrong, but the problem is a difference in capability combined with a performance cap that you can't power-scale your way out of.
The 100W suggestion is the same as the Intel board, though the Intel board can run standalone on the stock 60W supply without a battery by staying in a lower-wattage mode. The 100W problem specific to AMD is the inability to boot at all without a battery at under 100W, and not being able to hit max stock TDP with a 100W or greater supply unless a battery is also installed — even if it never draws from it.
From Framework's emails to early-batch buyers on the subject:
> Note that performance will currently be limited without the battery present. We’re working with AMD and our manufacturing partner Compal to tune and improve this. In the meantime, we recommend using a 100W USB-C power adapter to mitigate some of the performance reduction.