To be honest about it, how tough would it be for you to install basic vanilla DW?
DW is a tough game to learn, anyway. You'll need to understand how to navigate and change depth and when to do them to get the best effect. You'll need to learn how to deploy your sensors and how to effectively track and classify contacts before selecting the right weapon to attack them.
Along the way, you'll need to learn how TMA works and when it falls apart.
Stock DW will give you a good foundation on how to play the game.
Think about this question for a minute..
If you're a sub skipper, how many torpedoes should you be able to evade in any given battle if you want to be a good skipper?
The answer is "zero".
You're not supposed to be detected in the first place.
Having to dodge a torpedo or sonobuoy means that you've already lost the battle.
The good news is that learning how to do all of this stuff is the fun part.
Stock DW is set up to teach you how to play the game. Use that.
LWAMI and RA add more platforms and countries. They also change the dynamics to give all the platforms a more equal chance. This is because LWAMI and RA were designed for veteran players who had already seen it all.
So, take some time and learn the basics from the stock game before you move up to LWAMI or RA.
