Soldiers are nice, but what about when we can simply use missles to knock out their nations over night? Just looking at the damage we can do to their nations and they can do to ours means it's going to be loopsided in their favour. You are correct on the amount of soldiers they can buy in one go is higher then us, but the amount of soldiers they can buy is also limited by their infra. What are they going to do when all their infra is knocked out due to missile attacks? Without some serious WC spending on their account, they're going to die quite quickly. We also have advantages such as the bank, meaning we can store a lot more cash then they can and quickly rebuild our nations, they...don't have the bank, giving us an advantage.
I imagine the biggest threat ill come from their top tiers. I won't deny that when DBDC can knock out 1000s of infra in one hit, they could be a serious threat. However, DBDC are but one alliance, their smaller tiers will most likely die quickly.
As interesting as this debate is, can a mod clarify if it's allowed or not? Discussing invading other games seems borderline.