That equation doesn't look right to me, but I could be wrong. I think it's like this:

The angle beta (B) is asin(screen hex / real hex)
The angle alpha (a) is 90 - B (in degrees)
It looks like you were trying to use a cotangent (=cos/sin) to convert the sin to a cosine angle, but I don't know where you got the fixed 60 degrees.
I think the hexes in the upper left of your most recent post are correct. The ratio of the height of the pointy 'cap' to the length of the side won't change no matter what angle you view it at. For a side of N, each end cap is height N/2, for a total of 2N height. Changing the angle only changes the angle of the slanted lines.
@Lzzrd:
Overlapping units make it difficult for the user to select them, and it covers up the splendid artwork you did.
Screen clip from my previous project, with placeholder art.

That's a 3:1 angle on the lines and an overall 4:3 for the hexes. The angle of the city is wrong (iso), and the critter isn't quite right either, but I left it in to show how one could avoid overlapping.
Tourist