I can't comprehend why companies in strong positions need to acquire the strongest company in a new category at a premium. I'd think they'd want to buy the 3rd

I can't comprehend why companies in strong positions need to acquire the strongest company in a new category at a premium. I'd think they'd want to buy the 3rd or 4th ranked player in that category for a fraction of the price and then use their know how, clout and sales force to grab market share. That would be a win-win for themselves, the smaller company and customers.