I'd agree a lot of the girls are looking for a certain type of guy, muscled, with banter, good looking, confident, past that they don't care.
That's where Alex falls down, he's not got banter and he's not overly confident, nor is he ripped.
The guys are the same though. They want girls who are fit, have banter, are flirty and fun, and past that they don't care.
I think that's why Samira falls down, she doesn't really have banter, isn't flirty and isn't really fun round blokes.
Megan isn't much past flirty, but that seems to be enough for them.
Basically they all just want someone hot.