As far as I know, glue is never acceptable in professional jewelry making, regardless of the materials used (usually, none of them are cheap).
In your case, I see two slightly different solutions. Both of them require you to weld the pins (poles) to the ring. The difference is when you attach the pearl: before welding or after welding.
If the pins come with the head pre-formed, then you have only one chance, to weld the pins to the ring after you attach the pearl.
To be sure that the pins will not escape the welding and fall, you should make holes in the ring, install the pins into the holes, and then weld the pins to the ring from the inside of the ring.
Note:
- Both mechanical shocks (e.g., using a hammer for the forming of the pin head) and high temperatures (from welding) might destroy the pearls. You need to work carefully and plan ahead for everything you need to do. Jewelry making is not something to be done in a hurry and without thinking.
- As far as I know, there is no glue able to attach the pins to the ring without the risk of losing them later. And gluing the pearls directly to the pin and to the ring sounds like an abomination - which I would never do if I were to make jewelry.