From: Upstate New York USA
I think a little of both in your case. I'm a new player, with a vs. AI game at March 28, 1942. In my game, the AI is very careless about operating with surface protection. I've been running surface raiding with light (CL + DD) forces in the DEI since the beginning. Only in the past month has the AI started providing any heavy escorts for its convoys, and I've sunk almost 270 AK/AKLs, plus 29 DD and 80 SC/PB/E. Also, AI is sending carriers into the area with Task Forces of 3 CV + 1 DD. I haven't sunk any of them yet, but did torpedo one with a PT (Even a task force like that still outguns my light forces, since some of the carriers have 6" and 8" guns).
Your sub attacks have a large element of luck, of course. Based on your earlier post, I would say it's luck that you escaped the air attacks. According to The Roi-Namur Handbook on Dating Girls Named Betty*, the Repulse and POW will not be cruising around the DEI for very long, either by your design or by enemy action. See Chapter 4, "How to get F****d without it Feeling Good."
Bottom line - I would say the BB vs. BB encounter was a good fight, magazine hits and sub attacks are luck. The AI is aggressive, but not all that smart.
My 1-1/2 cents worth.
*Not coming soon to a book store near you.
"It's all according to how your boogaloo situation stands, you understand."