⏺️WDM-3C/twins means WDM-3C locos (2 Nos.) haul a passenger/express train
⏺️For example: see this
/blog/post/4202494 Link of 18048 - Vasco Da Gama - Howrah Amaravati Express is WDM-3A/GY/twins which means WDM-3A/GY/14009 and WDM-3A/GY/18792 are linked together to haul this train. So twins means 2 locos of same class must haul a train. WDM-3C/twins doesn't haul any train as of now. Your giving proof as single loco which is not correct. So this TL will go to Fixit