I still think speed, armor and armament were just as important as electronics. Firepower is having more guns than the enemy so you have more firing power at the start of the engagement. Have you never played Empire Total war?
You need a lot more then firepower to win in Empire, you need to know the battlespace, you own and enemy weaknesses. And the most important thing in Total War, you need to know tactic. But you must be that one of them, lads who die under my well directed flanking attack.
And armor is not that important as electronics, modern carriers are not armored at all.
The most important thing in Empire is veterancy and technology just like it is in real life. If you have a 5th rate with high veterancy against a heavy first rate in it's first battle then the 5th rate will win, it will outmaneuver, use the wind and reload faster. Also technology is vital if you have a heavy first rate from a nation with poor technolgy against the 5th rate from a nation with all the technology the 4th rate will win. Yes having tactics to suit you different fleets is very important, what ships do you normally have in your fleets to do flanking attacks? I normally have a fleet of 10 heavy first rates to cope with the enemies big ships, then a couple of brigs to kill the enemy rocketships, with my own 2 rocket ships protected by my heavy first rates.