I am flying SDF / DET / AMS / WAW. DL assigned all seats but the AMS to WAW (of course this portion is on KLM). One DL agent said they can assign the AMS/WAW seats in DET.

Can I get seats assigned in DET or do I have to get to AMS and take whatever seat is still unassigned? (PLEASE let me get an aisle!)

Any tips (I am traveling with 6 others in my group, all on paid coach fare)?

Thanks for the help!