While I can't find a comparison to the Ally directly, and it is more svelte than the Steam Deck, it also has fancier cooling and while these are comparable form factors, they're not really in comparable cooling and battery sizes
We're also comparing across not just GPU architectures but different GPU companies completely, where RDNA3 does chase higher clocks. I would also hazard a guess that none of these have sleep battery time like the Switch then?
We need to keep in mind how much Nintendo underclocked even the Tegra X1 in portable mode...I think higher expectations are going to be let down. Keep em low and be pleasantly surprised.