Is it just me or you are using same base mesh and just moving things around which cause them to look to a like .Why don't you start from scratch or at least use blank head base .It take only 5 min to block a basic head and it a good way to warm up before study + you will have a chance to be more specific with original head…
How long did you spend on one of those heads ?Whats your goal here ?Why don't you post reference too [I am pretty sure Arnold have rectangle face and you have giving him a round one ]Ok my guess here is that you sculpt 90% what you know and only 5-10 what reference is that's why they end up looking similar so you either…
Do you use zbrush angle of view by default 50 ? If you do I suggest lower it down to 30 or turn off prospective till you have something that look like a human [doing initial proportion measurements with prospective on wont lead to anything good]Also I suggest to take 10-20 min and analyze you reference before starting to…