If you want the printer to enforce specific job printing from specific trays then you need to configure the trays accordingly. Your current configuration has every printer tray as Any/Any. Normally you would only have tray 1/Manual Feed as Any/Any. The rest should be Letter/Plain, Legal/Plain, Letter/Letterhead, etc.
Try hardcoding values to the printer itself and let the applications send jobs automatically. The printer will know what to do from there and use the matching tray if one is available. Otherwise if there are no matches then it will send the job to Tray 1 or ask the user to load Tray 1 with the appropriate media.