The second one looks a like a buff orpington.
Did you get them from a feed store?
I would check up with a new picture at 6 weeks to see if it is a rooster or not.
Feather sexing is only reliable if that breed of chicken has the trait of fast feathering pullets and slow feathering roos.
Some breeds are reversed.
Buff orpingtons can be feather sexed but we will see what gender it will come out to be in a few weeks.
Yes they can be feisty
Mine was a porker and quite a charecter.