The light color and general profile suggests they are more zebra. You can see the more gentle slope of the neck from the shoulders on the one in the foreground, which is similar to the one on the right in the background group. Wildebeest tend to have a fairly sharp angle from the shoulder down the neck when they are grazing, and often appear darker. Other animals like Topi or Hartebeest have an upwards slope from the rump to the shoulders, and tend to (at least sometimes) hold their heads up more.
Hope that helps!