Fair. Paredes + Tucker is obviously a better starting point than Shaw + Tucker. To make a worse inter-sport analogy than your Bailey/Portis one, it's like having the draft rights to Bronny James, but he's actually a good player. There's an established trade market, and then there's what he's worth to the Lakers.
My less analytically sound angle to this argument is that I think I kinda want to open up what is essentially a starting spot to a prospect if only to widen the error bars/standard deviations of performance a little bit. Like, PCA played at a 6 win pace the last two months of the year, but the opening day plan wasn't to give him consistent MLB PAs (nor did he earn it in AAA). He got there through injuries, and yeah, could and probably will happen again in some form. But now we've got this upside that we didn't have before. In 100 Shaw seasons and 100 Paredes seasons, Paredes is going to outperform him most of the time. But I think Shaw's ceiling is higher (shiny new toy? maybe) and I think the path to a 95 win team given implied budget constraints is hitting on one or two more of the AAA guys. Said another way, given appropriate pitching updates (and we'd have essentially the same budget either way), I think Tucker+Paredes is a playoff team, Tucker+a 95 wRC Shaw+like Kevin Newman or whatever is a playoff team, but Shaw turning into a 3-4 win guy right off the bat opens up a much higher team ceiling in 2026 and beyond.