Haha, a well socialised pionus is anything but timid. They're independent and don't feel the need to be constantly on you, but don't mistake that for shyness.
Two birds that are friends are going to be more interested in each other than you. They will probably seek preening from each other rather than a human, and your companionship may not be needed as much or sought by the birds. However, parrots can also be broadly indifferent to each other - happy to share a space but not seek out each other's companionship. They can also violently dislike each other, and need seperate out of cage time. Same-sex pairs (either both male or both female) tend to be more stable, from what I've observed. With different-sex pairs, you either end up with a breeding pair - both will be interested only in the other, and the male in particular can get very defensive of his mate or territory - or you end up in a situation where one of the birds would very much like to pair up and the other isn't interested. However, these are all tendencies and there will be exceptions to all of these.
I do know someone who had what seemed like a very friendly pair of males. They only wanted headscratches from each other but were very friendly with their human family, would happily step up and would "help" with daily activities. Very sadly, one of the "males" had been misidentified and was actually a female. When the actual male hit puberty, he became very possessive of the other pi and very aggressive towards anyone who tried to interact with her. The female was not really that into him, and actually seemed rather intimidated by him. The owner had to make the sad decision to rehome both as she didn't want to keep a single parrot. Both went to homes with other pionus.
It's my long term intention to get another female pionus, but that's because I'd like another bird and I think Leia would benefit from having company. However, she really doesn't need any help with her confidence.