A new update came to civilization 5 just a few days ago and I found a very nice update that can help you manage your civ easily especially if you are starting your game in the renaissance era because most of the time you start with more units than your empire can manage and if you don’t recognize that you might come in crises. So the way that civ fixes this is through the menu bar.
If you look closely you can see there is a red icon with a explanation mark on there. This icon informs you about if you’r civilization has over capacity of units. So you can quickly change you’r capacity of units and make sure you don’t go into crises. Hope this help’s you.