I wonder if there's actually any kind of line between "inventing explanations" and actually theorising and studying the game's mechanics.

Obviously it's mostly pattern recognition, but that pattern recognition is partitioning parts of the board into classifications of what those sections are doing and whether to prioritise them or let it go in favour of something else, the immediate decisions within those sections are fairly logical. The more complex broader pattern recognition is how those sections will interact as they approach each other, which if there is that much inventing explanations where I imagine it comes in.