Coast Guard had a better team talent-wise than you had with your Lakeland team. This was your first season with the Lakeland squad, and Coast Guard had the same human coach for many seasons...tons of good redshirts. CG ran mostly power running formations (NDB and I), so I think your 4-3 was the right choice in this instance. Based on my short review, it just appears you were out-manned.
As for the 4-3/3-4 debate, it depends on your squad. All things being equal, I prefer a 4-3 because I like more pressure on the QB. INTs are as rare as chicken teeth in this game if you have a good QB, so I would prefer to put him on his back than try to rely on defending the pass. I also find it easier to recruit DL than LB because of the popularity of the 3-4, which is another reason I like the 4-3 presently.
Good arguments the other way, to which there are several good posts on this forum.
Ultimately, it comes down to talent more than anything. Pick a scheme and recruit to that style. Perfect your style and you should do pretty well.