Joseph: In the US, very rarely do Chasidim marry at 17. Perhaps the “Rebbishe”, but definitely not the norm.
Most Chasidim don’t listen to shidduch suggestions until 18, with some waiting till later (mostly 18 1/2 or sometimes 19). Engagements do occasionally happen at 17, when one is l almost 18. And since many Chasidic engagements span about 8 months, whatever the age then, they’re usually married closer to 19-20. Of course many marry later, as “Der mentsch tracht & G-t lacht”.