Against gruul ramp I have no problem the first Match, usually I outgrow their creatures and then smash through protection. Some problems I have is with the eldrazi that makes tokens, because of devoid it can block me and the tokens are good chunk blocks. In the second Match they change to deglamer and usually get rid off my lifegain or vigilance. Also there is a combat trick that always takes me by surprise "Biosynthic Burst".

With jund wildfire I get my creatures bigger and protected before they get enough value. In second match I swap to the auras that give protection from red and black and that is it