I'd be pretty surprised if Ascalon actually hits Zen 5 perf (I'm gessing more like Zen2/3 for most real world workloads). CPU design is really hard, and no one makes a perfect CPU in their first real generation with customers. Tenstorrent has a good team, but even the "simple" things like compilers won't be ready to give them peak performance for a few years.
All RISC ISAs are basically the same thing as far as compiler optimisation is concerned, and there is 40 years of work into that already.
I can't see any reason why the father of Zen and the designer of the M1 can't make a core for the simpler RISC-V ISA with basically the same (or better) µarch than the M1.