I understand where you are coming from, but look at Barca's badge. It has no iconic element, it has a catalan flag which is their identity, just like elements of the Manchester CoA are our identity.
Real Madrid's badge is certainly not an easy one for kids around the world to draw. These are the two biggest brands in world football, their badges don't fit the brief that you outlined, but it's not done them any harm.
As Gav has said, our badge needs to represent the club, the city of Manchester, be instantly recognisable as our own, and for today's modern marketing practices it's preferable that it's clean, simple, works in full colour and monochrome. Gav's core design does all of those things, it's an absolute no brainer for me.
Also one thing I've not seen mentioned is the CFG branding is a circular badge with the clubs name round the outside, and the inside should represent the city that club represents. NYC have the ivonic NY design, instantly recognisable as New York, Melbourne has elements of the Melbourne CoA, Manchester City should have something the represents the city of Manchester.
The crest with the ship and 3 rivers does that perfectly, that iconography is all over the city and the CoA. The eagle is not. The eagle has some obscure link to the city for a period of 4 years in the late 50s, and appeared on The Shite's cup final shirt. That's it. The connection to the city is looser than loose.
All CFG badges should represent the locality of the city where that individual club operates, we're by far the most important club in the group, so it's essential our badge represents our city. No matter what anyone says, the eagle is not a representation of Manchester.