A hostile takeover is more like a proxy war in which the shareholders of the company have to be convinced that there is a major need to replace the board of directors of the particular company. So a company does not necessarily need to hold shares in its target company.
A hostile takeover usually begins with a tender offer for some control in the target company, followed by a proxy fight, and at the end the acquirer has to buy all the important stocks in the open market. Hence, all important stocks must be bought for a hostile takeover. A few stocks won’t work!