I personally prefer the Shima rather than yugumo. I am using TA and running 20km torp. It is true that you will not hit the enemy that often but the contribution is on area denial. Forcing enemy to turn and can't shoot your allies IS very helpful in a game.
In my experience, your torp will always be spotted by enemy DDs regardless on the torp's version. Therefore, enemy will be able to dorge it anyway. With that in mind, range is more important than speed.
The other benefit for a long range torp is the safety from radar. When any of the enemy CA have it active, you receive a death sentence if the enemy consider you as a threat. Escaping 3 to 4 km from concentrate fire is rather difficult and highly dependent on enemy gunnery. If you are playing with 8km torp, the window of opportunity only appears in mid late game, where enemy DDs are all/mostly dead and CV lost interest with you.
I do agree that 12km torp is the most versatile setting for shima but with drawbacks. Russian CA with 12 km radar and enemy CV will have you spotted and all hell break lose again. I have had 2/3 of a game where I am either spotted by radar or FTRs as I try to approach and torp anything...
In conclusion, firing torpedo at around 13 km from the enemy is the safest way to play the ship with reasonable (but may not be visible) contribution. You are not too far from AA ships in your team and you can push closer as the game progress