Aren't you kind of stuck with smaller models on the mini though? Even with the pro you'd be stuck with a max of four daisy chained over thunderbolt and with the 160 gig memory bandwidth you'd probably be far better off with other configurations.
I really haven't seen any 16gb Mac Mini cluster setups running large models at any appreciable speed for the reasons previously provided. Do you happen to have examples that folks are actually using?
A m4 mac mini is better than al of these per dollar, msrp adjusted.
Hopefully by the end of the decade China figures out manufacturing at scale and fixes this.