All of those models have low-power CPUs. They have low single-core speeds, and Dolphin needs a lot of single core speed to run.
Melee isn't too demanding of a game, so you may be able to run at a decent speed, but try and get anything more demanding, and it will severely lag.
The Razer Blade Pro is a similar slim size at 6.6 lbs, with an i7-4700MQ CPU and dedicated GPU (great in Dolphin), but is twice the cost of the Yoga 2.
The Lenovo Y410p is cheaper (with the i7-4700MQ and a dedicated graphics card), at 5.5 lbs, but bit thicker: http://shop.lenovo.com/us/en/laptops/ideapad/y-series/y410p/
Melee isn't too demanding of a game, so you may be able to run at a decent speed, but try and get anything more demanding, and it will severely lag.
The Razer Blade Pro is a similar slim size at 6.6 lbs, with an i7-4700MQ CPU and dedicated GPU (great in Dolphin), but is twice the cost of the Yoga 2.
The Lenovo Y410p is cheaper (with the i7-4700MQ and a dedicated graphics card), at 5.5 lbs, but bit thicker: http://shop.lenovo.com/us/en/laptops/ideapad/y-series/y410p/