You are taking the DS9 analogy too far, or perhaps the wrong way.
I beleive we will find that ONE is more of a conjoining of intellects. Perhaps it can best be described as the "Great Joining" of the DS9 Shape Shifters. It appears to only take effect when in contact with the Groove, which is likely a wormhole. In that "odd configuration of space" there may be the environment necessary for the comingling of the minds. ONE would then be the super intelligence thus created.