TBH I was a little disappointed that we signed 2 CBs as it will mean Holgate is unlikely to start. But team over player and if the we bring in players that cause others to miss and its for the greater good that is life. For me as long as Silva doesn't do what every manager before him has done and pick his favourites irrespective of form. If Zouma and Mina are pulling up trees then play them. But if Holgate is outperforming he must get the nod!. He will get game time though, although defenders are often not pulled from games..
Think of the upside, less chance of Keane/Jagielka playing many games. Holgate will get game time - like previously stated by poster above, I don't think it's a foregone conclusion that Zouma/Mina slot in ahead of him every week.