Totally! His menswear is quite obvious but every season, you have an Helmut vibe ( and actual designs) in his womenswear.
+ Don't forget Gaultier! Riccardo also copies Gaultier.
Here's my list of the most copied designers in the past 15 years:
-Nicolas Ghesquiere
-Helmut Lang
-Gianni Versace
-Martin Margiela
-Tom Ford
-Azzedine Alaia
-JP Gaultier
-Miuccia Prada
-CDG
-Yohji Yamamoto
Every season, we literally see obvious copies of those designers. The funniest part is that NG who is one of the most copied designer has also borrowed a lot from the people in that list. But i think it's mostly because those designers were influencial in building his own aesthetic.