I do agree that you have two very cute budgie girls. The one on the first picture looks younger, she still is heavily barred, so hasn't started the first moult yet. I'd say she is 3 months old. She is a sky blue recessive pied.
The budgie girl on the second pic is older, I see the tan starting to creep in on the base of the cere, between the nostrils. I'd say she is close to reaching 6 months old but not quite there yet. From that pic, I think she is a grey yellow face type II recessive pied budgie.
If you have a big enough cage for all 3 pairs and the introductions go smoothly, you may not run into problems. However, you should pay close attention especially when your females go into breeding condition, this is when usually the trouble begins to surface and there can be some bad fightings.
In order to prevent fightings and general animosity between my birds, I prefer to house each pair into their own cage. By doing so, potentially stressful situations are avoided, there's no vicious fighting and the light bickerings are put to a minimum.
Best of luck with your new girls and their adaptation to your flock!