This is just an out of the box idea (many may not agree - understandable, but just a thought):
Why not speed up 12311/12 and make it a complete AC SF train from HWH to Kalka? It can run overnight between Delhi & CDG/Kalka and return (like a premium train), and between Delhi and HWH it can act as an affordable alternative to Rajdhani (like Gareeb Rath)? It can have 1AC, 2AC, 3AC and 3AC Economy classes only, and run with only 18 LHB coaches (fit for Kalka station's length).
...
more...
Meanwhile 12329/30 WB Sampark Kranti can be extended from ANVT to CDG, and can be run between KOAA and CDG on daily basis (if not daily, then 4/5 days a week). KOAA has capacity to handle additional rakes/services, and also SDAH can be freed up by transfer of service (SDAH can - and should, focus more on suburban EMUs). Rake sharing arrangement with 12379/80 Jallianwala Bagh can be cancelled and services can be continued separately between HWH and ASR.
Maybe NR can take this up (like 12449/50 Goa SK and 12217/18 Kerala SK). As and when situation demands, remaining 2/3 days (days when WBSK doesn't run) can be used as RSA for a new train till NJP as North Bengal Sampark Kranti (via PPTA-KIR). Anyways there is huge demand for a separate premium superfast train from Siliguri/North Bengal to Delhi, why not fulfill that demand too in the future?
What do you think, gentlemen? Any alternative suggestions?