For those of you with an Android phone I would recommend the Axis and Allies simulator. You plug in what type of game you are playing, any special conditions that exist, what unit types, what type of battle, etc. and it runs the battle 1000 times and let’s you know the outcome. We actually ban it from games, but helps when considering a tactic or in post-play. Obviously there are other factors to consider other than the odds, but it can’t hurt.
Here are the results of a few sims I have run for the amphibious assault of 1 defending infantry vs. the various transport arrangements.
Attacker : Defender | Attacker Win Avg. | Defender Win Avg. |Total Destruction |Attacker avg. IPC Loss | Defender avg. IPC Loss
Inf. 2 Inf. 1 67.5% 27.1% 5.4% 3 2
Inf. 1
Art. 1 Inf 1 86.7% 9.3% 4.0% 2 3
Inf. 1
Tnk. 1 Inf. 1 90.1% 4.9% 5.0% 2 3
As always I think the best bang for your buck is Inf and Arty. Again, there are other factors to consider, such as your overall objective.