You want to avoid stretches wherever possible.
On a 34" longscale bass, the first three frets can be covered by four fingers. Carol Kaye shows this in one of her videos. It is better to keep the fingers bunched instead of splayed out whenever you can.
This, IMO is where most of the problems occur on a longscale, because as you move up the neck it gets way easier because the frets are closer together.
The frets nearest the headstock are where most of the issues occur on a longscale.
I have great big hands, but its' one of the reasons I ditched longscales.
I reveled in stretching when playing one for ages. Until it all went south suddenly and I couldn't use my strained pinky.
I had, later on, switched to Carol's method of fretting (which is also described and used by others....videos on YT) but I just plain didn't like any method.
So for me, it was a switch to shorties... and I haven't had a problem since.