Sorry I’m late to respond. I have 2 rainbow lorikeets that I purchased at seperate times. I do not have any experience with other lorikeets besides rainbows, so yours behavior may differ.
I wouldn’t suggest mixing two different types of lorikeets, but I don’t have any experience with that.
I can tell you how I introduced mine-also it’s good to point out that my first lorikeet was under a year old and the second had just been weaned when introduced. I think this makes a big difference-I feel the younger the birds the more likely they will accept each other.
Here’s how I introduced mine- each step takes 1 week or more
1- quarantine- the new bird was seperated from all other birds but they could hear each other. This was the hardest part as they screamed back and forth all day long. Quarantine is usually 30 days.
2- sighting- the birds are introduced in travel cages in a neutral location. Neither are let out or allowed to touch each other. You can do this a few times a day and move them back to their own cages.
3- new bird is brought to original birds’ cage- keep the new bird in the carrier and let the original bird out of its’ cage. Let the original bird climb on the carrier but keep watch. They can bite each other through the cage bars.
4- neutral location (both birds out)- I chose my shower for this. My lorikeets are not scared of the ground and it was a place I could easily clean. Let both birds out and stay the entire time to supervise. Let them be together 10-20 minutes at a time and then take to their seperate cages- which are now placed within viewing distance of each other.
5- if all is well begin letting them both on the original cage supervised. You may still need to seperate at times.
Once housed together make sure the food, nectar, water bowls are seperated to reduce fighting.
You may not have to take all these steps but the slower the better. My lorikeets are very aggressive to other birds and have no problem trying to kill my macaw. They’re like the chihuahua of the bird world-they don’t know their size!
Good luck!