Snake doesn't understand how someone can be so consistently nice and with multiple people. But Snake recognizes that Hershel is the peacemaker of the group. Also a bit of a doormat.

At the same time, Hershel has given Snake a lot of good advice on how to be less of a jerk and consider the feelings of other people. Especially Heiji.

He's also come to the realization that Hershel rather delighted in watching him and Heiji fail to recognize the attraction in each other. Which genuinely annoyed him as Snake likes to consider he's mostly perfect in dealing with his personal affairs. I think he's beginning to see the shitlord side of Hershel and given that Snake can be an arrogant man at times, he might be quite entertained by the thought. Hershel is becoming a good friend. Not on the same level as Heiji and Hershel are bestest bros, but just their own kind of friendship and I think that's pretty cool.