For me, two is two too many. But I tolerate them because I was promised by the wiki "At any time, there can be only one wandering trader naturally spawned in loaded chunks".
I'm pretty sure I've met those conditions, and my 1.15 pre-2 world (started on an early 1.15 patch) has two. Screen pics shows this, they are separated by about 25 meters, tried to get both in pic.
So, before I report this as a bug, please let me know if the "only one at a time" rule has changed. Thanks/Lon
p.s. The seed is 4111111111111111 and the world is called "Visa". 7.5 kudos for anyone who can tell me why. It's otherwise a pretty neat world.