Alex is nice - not agree that profile is bad - but still needs more work - yes. The front is very recognizable though i suggest to backup this version and try to catch a bit more angry expression. And yes pay attention to the nose and chin part on the side view.
Aguero is very interesting but side view is far from correct. The nose is absolutely wrong - he has another type of structure in life. What is really nise - the eyes - you have almost caught the expression i wanted to see. But head shape needs lots of fixes. Keep working