Electrical - Is this legal to code?

I dug a trench from the garage to a toolshed, and put about 30 feet of
12-2 UF cable underground to the shed. Before filling the trench, I
decided that maybe it would be best to put two of these cables in so I
have two circuits in there, mainly because it gets so hot in there that
I might put in a small air conditioner.

The first cable I installed was some UF cable that I got at an auction.
It's unused cable, but apparently old stock. The reason is that it does
not have a ground wire. The second cable is brand new, because I did
not have enough of that old stuff to go twice. I did not realize there
was no ground in that cable until I filled the trench, or I would have
just bought all new cable.

Anyhow, I ran one cable to the left+rear of the shed, the other to the
right+front. After I get it all stapled and into boxes is when I
realized there is no ground on that one cable. Oddly enough they both
look the same. They are gray and 12-2 UF. I did not know they even
made gray without ground. I recall some old white UF that came without
a ground years ago.

Anyhow, this is what I plan to do. Both cables are on a separate
breaker at the source (garage). In the shed, I will ground the ground
wire to the box from the cable that has a ground. On the second cable
without the ground, I'll run a bare or green wire to the other circuit
that has the ground wire. This will just be a bare copper wire (or
green insulated) across the rafters to a box on the other circuit.

Electrically speaking, this is a completed ground, but I'm wondering if
an inspector would allow such a connection?

My other option, seems to be to run both cables into one box, near where
they enter the shed. That way, there is one ground wire to that box no
matter what. Then run my outlets and lights all to that box, but use
the hot and neutral wires as planned to have two circuits. This might
make more sense but will need more materials to do.

By the way, this will not be inspected. This is rural property and they
dont bother with small things like this. I'm only asking both for
resale value (at which time there could be an inspection), and just to
know how this would be viewed.