"Or the weaker will be sucked into the stronger."
Uh, in other words uh... merging?
Actually I think it's a matter of terminology that you "mergers" are using here. You act as though when the 2 storms meet as a "merger" it turns into one, big super storm. That does'nt happen. And it is'nt a merger. It is one storm actually dominated the airspace that the second storm cannot survive. The second storm does'nt increase nor does it enhance the larger storm except maybe introduce more moisture.
But they both cannot live off the same hot water simultaniously. After a storm passes, it uses up the hot water for energy, if 2 storms collide they more likely bounce off of each other. It is much more likely that the larger storm will "eat" up the smaller but it does'nt increase it's strength because of it. Hot water and low shear allows a storm to breathe and get stronger.