Vagulus:
You might want to dig out your old Strength of Materials or Machine Design text books, assuming you didn’t sell them used, for a six-pack. Good texts will have something on bolted connections. Also, any of the Structural, and specifically structural steel codes, will have info on bolted joints; spacing, edge distances, spacing btwn. rows, etc. And, they will also have info and methods for analyzing net sections around the various bolt patterns to determine the critical load path for a given bolt pattern. Right now, in your sketches and with their proportions, it looks like your bolt size, spacings and edge distances are much to tight for a practical joint. And, in a more detailed analysis of a bolted joint, you should give some thought to the fact that all the bolts don’t come into play at once. Some of them must be in bearing and starting to yield in bearing before others really come into play. There are also issues of how tightly you fix (tighten) the bolts.