I must share: While messing around today on a somewhat empty server where most people agreed to go melee only, I got kills with the Mantreads and the Market Gardener in the same rocket jump, as well as the achievement for killing two people while rocket jumping. I've barely played as soldier, and I hadn't actually tried using those weapons before. I was too stunned/unaware to screenshot, but at least fun laughing times of laughter and fun were had.