The answer to the headline question is “yes, but….”.
I am left-handed. I have always played with my left hand on the fingerboard and the right hand plucking or holding a pick. I started guitar and didn’t know there was difference. I was in the 7th or 8thgrade before I found out you could get a mirror image guitar. But there really wasn’t a difference. How many string players have you seen in an orchestra bow with their left hand? If you are left handed, remember that most of your dexterity is probably in that hand.
In fact, you all know this guy, right?
Would you be surprised to find out that Sir Paul is actually right-handed? Yes, he is…well, there is some controversy. People just assumed for years that he was left-handed because he played bass with his right hand on the fingerboard.
The real challenge is that right or left handed makes no difference when you start out – Left hand on the fingerboard, right hand on the strings to pluck or pick.
All lefties know the world is right-handed and you have to be ambidextrous to one degree or another – always much more so than right-handed people.
Of course, the original question – is everything the same if you are left-handed? Yes. If you play with your right hand on the fingerboard, is it the same, yes…unless you are one of the people who play with the bass strung upside down. Not something I can think with, but Jimmy Haslip does it extraordinarily well.
I never change a student if they have been playing for any length of time but if they are just starting, everyone starts the same – left hand on the fingerboard. Every bit of dexterity on a bass guitar is learned, so you learn the dexterity whether you are left hand dominant or right hand.
It is possible that when beginning bass guitar, the dexterity might be slightly better playing left-handed. I will confess the only, and I repeat, only problem I ever ran into with my right hand was learning slap bass. My right hand didn’t seem rhythmically coordinated enough to do it. But, guess what? I broke out the metronome and worked it out slowly (and with a bit of help from Vic Wooten) and now it is fine. But dexterity can be learned. Also, as a teacher, it is a little bit odd to watch someone play with their right hand on the fingerboard. But you quickly adjust to it.
Anything in music can be taught if the student has the ambition and drive to learn and the teacher is fully able to get any musical concept across to the student.