Had quick read about the Tonypandy riots, I had assumed there were more troops deployed than actually were. Seems Churchill was reluctant to send them he thought the police could manage without them. Wiki seems to suggest that it wasn't any specific action by the army that was the issue just that they were there which in turn caused the strike to collapse.
Seems he wants the greens at one debate. Publicly its because the greens have on occasions polled higher than the LDs. Privately if he is going to be attacked on the right by UKIP then he wants the others to be attacked on the left by the greens.