It is an unfortunate truth that there are many people that colony breed and advocate it, and there are also many people who say breeding birds over 4-5 years in age is an acceptable practice. Those with such a mentality can only be one of two things when it comes to ethical breeding for those of us that have been raising them for many years, and have followed the example and advice of others that can actually be respected when it comes to the birds well being:
1. They are only out to make money and/or their own enjoyment of breeding birds is more important than the birds welfare. 2.They are truly uneducated and simply do no realize it because they have followed the poor example and advice of others who while they might have years of "experience" if you wish to call it that, they likely fit #1's characteristics and really are not at all an example worthy of imitation in any way.
Just because something can be done does not mean it should be done. Most birds in the wild do not even live long enough to get past the ideal breeding range, so comparing them to the budgies raised in our homes is simply irrelevant. Like humans, animals encounter more problems themselves and with their young when they breed at too young or too old of an age. A 40-50 year old woman can get pregnant given the right circumstances, but is it wise for her health and the babies? A 8-10 year old child can get pregnant, but is this something we encourage when it comes to the mothers and child's well being? Obviously not, and the reason being that the odds simply are not good that there will be a happy and problem free outcome which a woman can often have when she is at a more ideal child bearing age
Budgies simply go off of their instincts and surroundings. If given the chance to breed they will try their best to keep the species going. When we bring them into our homes it is our responsibility to do what is best for them as we are giving them circumstances they would never encounter in the wild.
What you are seeing as cute and natures way, we see as a poorly planned breeding between a hen that is far too old and a male that is obviously not mature enough to raise a clutch even if he is a year old.
What you see as a pair of males that have chosen to help a hen incubate her eggs, we see as two males which are so desperate to follow theirbreeding instincts given that you have provided nest boxes, abundant food, and day light hours but not enough hens for them to pair up with so they are trying to find an outlet for their frustrations however possible.
I hope you understand that what we are saying is coming from a good place and we are simply trying to help you avoid the common problems that result when you breed unethically, even if it is well intentioned
I know very well that you might not change anything from reading this thread as you seem to be very content with the situation, but hopefully others will read it and see the wisdom of the advice we have given when it comes to the birds well being and breeding them ethically.