Six in the second place answers a question about motive rather than about outcome. Read as a changing line, it tells a querent that the alliance under consideration is sound so long as the impulse toward it comes from genuine conviction and not from a fear of being left out, a need for protection, or the simple pull of what everyone else is doing. Firm correctness is named as the condition of the good fortune, and the line's commentary makes plain that joining on these terms costs the querent nothing of their own standing.
Flipping this soft line to firm changes the lower trigram Kun into Kan, water, so that water stands over water and the figure becomes The Abysmal, King Wen 29. The doubled trigram is one of the hexagrams of danger, and the transformation reads as a warning about the same virtue overplayed. Inner constancy, hardened, stops being a source of attachment and becomes a repeated plunge into difficulty, sincerity turned into stubbornness with no yielding surface left for anything to join to.
A reading here therefore counsels a querent to hold their own center while staying genuinely open. The favorable direction is to remain soft in position and firm in conviction, since it is precisely the yielding placement of this line that lets an honest inward motive find the correspondence it is looking for.