The two sides have been working in tandem on the training pitch, and Howley believes that has been hugely beneficial for both sides.
"Our Under-20 side have played an integral part of our preparation," said Howley.
"We have full contact and unit sessions with them every Tuesday which really puts the pressure on the players and helps both teams.
"Preparation in international rugby is so important, especially when you don't have a lot of time.
"Having the opportunity to train with and against Danny's (Wilson) side mean the sessions are closer to game intensity.
"It is hard to replicate that level in training but by having two full squads against each other helps us take that step up.
"We are benefiting from it and so are the Under 20s and it's great to see them doing so well.
"They have continued from where they left off in the Junior World Championship last year, winning all their games so far in the Six Nations, and playing some really good rugby too."