A good tonearm should not have a sound of it's own like the Tri Planar, Schroder CB and Kuzma 4 Point 9. A good cartridge will sound exactly the same in all three arms. I can say the for the Windfeld Ti which I have heard in all three arms on a very well balanced system for what it's worth.
The reality is it doens't.
I have swapped arms many times using the same system, same turntable, same cartridge - all arms have different sonic signatures even the most expensive.
The most recent example was when I set up a Van Den Hul Colibri
on 3 arms in the exact same system - Moerch DP8, Helius Omega, Kuzma 4Point11. Basically I swapped out the arms on the exact same TT/Cartridge in the same system.
Each arm/cartridge sounded noticeable different. In one case - the Helius - it was so different you would not have recognised the cartridge. Just so happens the Helius has an extremely low effective mass relative to the others.