Actually, (orthodox) Marxian economists would likely be opposed to full employment policy and welcome an increasing reserve army of labor since in Marxian theor

Actually, (orthodox) Marxian economists would likely be opposed to full employment policy and welcome an increasing reserve army of labor since in Marxian theory it's met by a rising organic composition of capital (ratio of "constant capital," i.e. capital goods to "variable capital," i.e. wages and supplementary funds), which in turn entails a fall in the rate of profit as labor is substituted in favor of machinery, and an eventual breakdown in the accumulation of capital. That said, Marxian economists have evolved significantly and a lot of them have since converted to some form of Post-Keynesianism.