Grant:

Wow, that is a very ambitious plan!

Here are some variations:
Instead of dropping off Whitney to Crabtree, consider heading south over Discovery Pinnacle from Trail Crest, across Crabtree Pass. That will take you into some beautiful country. There are several un-named lakes, and then you come to Sky Blue Lake.

There is a report in this forum somewhere covering that route -- known for the very sandy slog up to Discovery Pinnacle from the lake nw of Crabtree Pass. But you would be descending, which ought to be fun.

If you set up a base camp at Sky Blue Lake, you could then climb Langley, maybe via The Major General, rather than heading all the way to Army Pass. You could then return to Whitney via Discovery Pinnacle if you were up for the sand slog.

I am not sure, but looking at maps and the satellite view, the traverse you ask about looks too rugged without technical gear. Here's the gmap4 interactive map link -- zoom in/out, switch to satellite and 't4 topo high', click/drag to change the view, etc:   Gmap4-Discovery-Mallory

But I do think you could head northeast from Sky Blue Lake and go over Arc Pass to the Main Mt Whitney Trail, or cross the pass just s of Mallory, and descend to Meysan Lake and return to the Portal that way.

Good luck on your trip. It sounds like a great adventure. And be SURE to report back here how it all works out.

(If you need that Discovery Pinnacle hike info, ask, and someone here can look it up.)