Early Game Maximizing income vs long term growth.

[ano]

You have perfect infantry with MA Pythium which will do the same job for you for much lower price. And that is the answer to you question.
And generally I am not a fan of making gold-costly armies of "uber"-units if you don't take very good scales and are not aiming for rush or early war. That's just because you almost always can do the same with cheaper troops and upkeep will come for you shortly. And it is the main thing you should be worried about. Wise player will watch his upkeep thoroughly.