What exact equipment are you speaking of? I definitely don't consider Trane inferior to Lennox.

IMO

Whenever people have posted Lennox and Trane quotes, it seems the comparable Lennox equipment is less than the Trane. I think this is the primary reason for choosing Lennox over Trane.

I suppose that you mean that Lennox is priced lower, costs less money.
I do not know what quality level of equipment he chose for this custom house. But the house is upscale for this area. It is entirely possible that it is the top-of-the-line Lennox equipment.

If the house is being built as a custom type offering, then I would expect it to have at least two HVAC systems. I am doubtful though it would have top-of-the line equipment included in the base price. Most home buyers don't research the model of the HVAC equipment, so this is not where the builder is going to spend extra money beyond a basic system.

Some of the facts about this new house are unknown to both of us. I know nothing about the specific equipment being installed. But this young man grew up within 250 feet of the house site, is an electrical engineer PE, and appears to be going for quality instead of the biggest house for the money based on other things that are observable. For those reasons, I suspect that the better grade of equipment is his choice.