There was a technical paper on tail rotor design way back in the 1950s that said top turning aft was the best way to go.
Why were the various machines made the other way round? Could be anything from not having to re-qualify a new gearbox to not-invented-here syndrome.
The Lynx changed tail rotor direction of rotation and it made a world of difference to handling, performance and noise.
All the civil Bell 205 series appears to have the tail rotor top going aft.