diesel-electric??
cutting-edge subs???
oxymoronic
A “cutting edge” diesel submarine was what surfaced next to a US carrier I think it was last year or so, the entire fleet didn’t detect it. It rattled a lot of people to the bone. I wouldn’t disqualify someone’s hardware from being good just because it’s not in inventory in the US navy.
It always pays to assume that the enemy has better gear, training, and morale than you, that way you’re always prepared for the worst, and if it’s not the case, the cakewalk will be a pleasant surprise.