Are your developers too egoistic for you? If you said yes, then YOU may have a problem. A strong ego is a good thing. Ego shows me a team that wants to affect change and cares about the product they are developing. If you think your developers are overly egotistical, well, that's your problem. It takes a lot of effort that is contrary to basic human nature to be overly egotistical.
"But I really, REALLY think my guys have TOO much ego." If this is truly the case then it is because they feel as though you or the organization is not doing the "right thing". They are cynical of you. They are fighting back.
"Thankfully, my team displays no ego at all." If your team is not egoistic enough then perhaps they feel defeated by your asinine policies or lack of support. They can no longer affect change positively.
A healthy ego is good, foster it. When it starts to get out of control you need to ask yourself why?