First time model - 'BLAA' head

Hello there,

I’m creating a model for ArmA 2 and Operation Arrowhead using the Battle: Los Angeles Aliens (or BLAA) creatures. The obvious place to start is with the head and I’ve had a few goes with manipulating the head shape. Namely using subdivision surface under object modifier to get the right look. I can’t quite get the right shape, I’m going for an almond shaped head (as seen from the front) which has one side slightly more curved side than the other to give it an organic look. Which is accurate to the actual creature design. Here’s my reference material:

Infantry Caste

Any tips or suggestions would be very much appreciated. Thank you!

Here’s what I’ve made so far:

I don’t feel I have the exact shape. And the side vertices might be a problem as I don’t want ‘pointed’ sides. But it’s the closest I’ve managed to get to the shape of the head. I’d really like some feedback, any feedback just to see what else I should be doing.