Thought Experiments (re: links, domain-names, 301-redirects)

People in my company are debating several website structures, and we have questions about SEO principles and outcomes. The real situation is a little more complex, but these idealized “thought experiments” illustrate our questions about SEO:

****Imagine two websites of “X incorporated”, westX and eastX, located on the west and east coasts. Both websites have the same internal structure, differing only in their domain-name:
****WEST website has a homepage, westX.com/index.htm, plus “interior” pages inside a west-directory, westX.com/west/west1.htm, westX.com/west/west2.htm, and so on.
****EAST website has a homepage, eastX.com/index.htm, plus “interior” pages inside an east-directory, eastX.com/east/east1.htm, eastX.com/east/east2.htm, and so on.

****westX is an old website, with many links to the west-homepage, but eastX is new with no links to the east-homepage.
****some links also come to west1.htm, west2.htm, etc, but far fewer than to the west-homepage;
****even fewer links (compared with west1.htm,…) come to east1.htm, east2.htm, etc.

Now imagine three different merging-structures between westX and eastX:
****1) The two websites are semi-merged into one website, and its homepage links equally to all interior pages, with the same links to west1.htm and east1.htm, and so on. The homepage is www.westX.com/index.htm with 301-redirects of all pages in eastX.com to westX.com. (Notice that the high-status homepage retains its original URL where the many links came to.)
****2) Analogous semi-merger, but reversed: Again, the homepage-links are equal to west1.htm and east1.htm, etc. But now the homepage is www.eastX.com/index.htm with 301-redirects of all pages in westX.com to eastX.com. (Now the high-status homepage is 301-redirected so its URL now has a different domain-name than the URL to which all of the links were made.)
****3) The two websites are independent, with no 301-redirections, but there is only one homepage; it’s on the westX server with its original westX URL. This homepage links equally to all interior pages, with equal links to west1.htm and east1.htm, and so on.

RELATIVE RANKINGS
****With any of the merge-structures, west1.htm has more incoming links than east1.htm, so its SE-ranking should be higher than for east1.htm. But will their RELATIVE SE-rankings be different with merge-structures 1 and 2? / I think that if the only “relative rankings” factor for SE-rank is LINKS, 1 and 2 should have equal SE-outcomes, but if 301-REDIRECTION is also a factor (if pages having the same domain-name after a 301-redirect are less impressive to SE algorithms, for some reason, compared with un-redirected pages having the same domain-name) then there will be a difference because the un-redirected pages with westX in their browser-URL will get a higher share of SE-status from the westX-homepage, compared with redirected pages that also have westX in the URL shown in browsers. But I’m not sure.
****I think the questions above may be trivial if 301-redirects are 100% efficient in transfering link-credit (which I think is true although I’m not sure), but I’m less confident about the answer for this question:* Will the relative SE-rankings change with merge-structure 3, compared with 1 and 2? I think that if LINKS are the only factor in determining SE-rankings, the eastX-pages should rank just as highly in 3 as they do with 1 and 2. But if sharing the same domain-name as the high-status homepage (with westX in its URL) is another positive factor, then the rankings of eastX pages (east1.htm, etc) will be hurt by structure #3. But I’m not sure.

ABSOLUTE RANKINGS
****Will there be any overall advantages, when all things are considered (for both westX-pages and eastX-pages), in the SEO-outcomes for merge-structures 1, 2, or 3? I think there might be no differences, but I’m not sure.

Above you’ll see “I’m not sure” after each of my tentative un-confident predictions about what will happen with each scenario, so I’m hoping some of you can provide expert advice about the SEO principles. Thanks.

gadgetman