some thoughts:
1. assuming as 'true' the possibility that provided Pentium gold is capable to handle raid5 computations on 4bay config
2. taking 4 x 10tb wd red pro, with some 200MB/s write [i also took medium speed, from various online tests], no nvme cache
let's say that, in raid5, maximum speed is calculated in the same way as total capacity - so, 3x200MB/s = 600MB/s write speed - read speed being higher, eq. 700MB/s
...a lot less that 10GBe transfer capacity!
for 4x4TB SATA SSD will have, following my assumption, ~1600MB/s - only if the cpu is able to perform raid5 computations. adding nvme caching will raise these numbers, most probably - but only using thunderbolt; it;s possible to have 12Gb/s using all ethernet ports, but will require correspondents switch, clients and so.
anyway, single thunderbolt connection will give some 3,5GB/s transfer speed, same as a nvme pcie x4; using both ports, speed is halved. i/o numbers will be big enough to help, though, two editors work in the same time (staying near the NAS, giving the fact that thunderbolt cables [even active ones] aren't too long...).
i'd like to be corrected, if my assumptions are wrong.