There in lies the difference..no longer is the MSC to be composed of existing units..instead its jawaans will be part of an ab intio formation (ergo the long lead time) which will be an over the counter addition to the eastern command. The officers will most probably be drawn from existing units so as to have an experienced command setup.
Now on to its utility. It is needed for one simple reason- the force structure on both sides of the LAC is actually quite similar and ironically enough in numbers and equipment we have parity give or take by a margin of a single armored regiment. BUT such a picture albeit accurate factually is misleading, why, because of our piss-poor infra in the NE and even in Ladakh. The SARDAP-NE project for rapid road infra in the NE is going slowly while a large stretch of the roads in TAR are all-weather roads, this creates a rather severe problem for us, for although the formations positioned around the LAC might be at a parity with their Chinese counterparts the Chinese in the event of a conflict can introduce fresh troops into the theater with relatively greater speed and this means that once the troops are committed on both sides it is the PLA which will have the first shot in exploiting any breaches they can open up (warfare being highly dynamic, one needs to have the ability to hold forces in reserve and deploy them with adequate speed to exploit any and all opportunities which arise after contact, said opportunities can often be fleeting) by having mobilized quicker than us even though such a mobilization cannot be hidden (irony of ironies that the 3 or so weeks it will take them to bring in the divisions to build up numerical superiority will still not be enough for us to match that quantum)*. Thus the requirement of a new corps over and above the existing forces of the Eastern Command.
That having been said, the corps is not meant to just initiate an offensive but is meant to be agile and kept in reserve so that we can deploy it across the theater as and when the need arises. This MAY include an offensive push north east of Sikkim so as to alleviate pressure from say another formation which might have been over-run and to then get the Chinese to commit troops in reaction. In short we are giving ourselves options so that we too can effect some active strategies rather than fighting a reactive war.
Lastly, even though vertical envelopment of the NE is already pretty impossible, given the non-availability of "last mile" connectivity to the "border" the Chinese could very well enact a high intensity short duration campaign to slice away a portion of our territory (lets say across the front at AP up till a depth of 15km give or take), were they to get the jump on us our own forces need to be mobile enough to meet force with force in such a fast developing scenario- that too is meant to be handled by the MSC.
*This aspect of the exact nature in which mobilization on both sides will occur and exactly how time sensitive opportunities can therefore be exploited will require greater elucidation but you I know will have gotten the gist of it.
Btw I hear our brother Jalebi just made Mod...remember when we prospected him and marked him as a talent?
