this is a true statement in general, but this guy is at an earlier phase of development: maintaining a conversation with a girl (while not dreaming up 2D diagrams of the participants' positions in the interaction using circles and grids). So he is at an early beginner stage.

In light of that I think he should initially focus on natural easy conversation with girls. PUA stuff of intent, isolate, escalate, close etc can come in the future when he has developed into a more chilled guy.

A brief Google search yielded this for him to read:

Conversation Skills / Tips: How To Have A Good Conversation

How To Be Genuinely Interested In People e.g. he could have used the "show interest / enthusiasm" approach within some follow-up comment on school reunions