Problem is there was not a huge migration from central asia to north india with mughals otherwise if let's say the immigrant tadjuks , uzbeks, Turks significantly alter the demographics of north india then conquering and maintaining the lands of central asia all the way to samarkand bukhara was possible
There were more Indians than Turks or Tajiks, even along the Indus. Maybe if the Oirats are more aggressive and drive a lot more Turks South to Afghanistan. But I'd say the Turks, Tajik and Pashtuns will assimilate in the dominant Indian Islamic population, considering how easy Turkic and some Iranian populations assimilated.
If the Mughals assimilate into the Northern Indian populations (Punjabi, Rajput etc... which they did) and focus on those certain groups to Islamize them (which they didn't) they could get a secured North Indian core. The South will still be problematic although I think it was the rapid conquest of Deccan by Aurangzeb that weakened Mughal capabilities. Divided over time, they might have secured the South of India as well to the tip of the Subcontinent, albeit with vassals or semi independent provinces.
Militarily, big show off Armies were not optimal for battle either. Smaller efficient forces will help them rather than 300k troops in Kernal for example...