Most people don't know Tadasana from a hot sauna and that's okay.
But I often hear Yoga teachers calling Tree Pose Tadasana when it's actually Vrksasana.
Does it matter?
Yes. It does. But only if you're a yoga teacher and you are teaching the class and using the words. So, I'm not that picky.
But yeah, I think you should know Tadasana from Vrksasana from Balasana from Supta-Virasana if you went through yoga training and are also willing to spit out Sanskrit while instructing. If you're going to use the Sanskrit, you need to know your shit, because your students often know their shit, or are trying to learn their shit from you, and as an instructor it's your responsibility to do your job to the best of your ability.
I teach school also and I would be sucky at my job if I told the kids nouns were actually verbs. It's misinformation and it should not be passed on to others... that's not what good teachers do.
So... learn the Sanskrit, or lose the Sanskrit.
And, don't be afraid to screw the Sanskrit up along the way.
Trying is doing.