The composition of sl(2) representations is the 'plethysm' of the respective representations. Crystals are a powerful combinatorial tool for representation theory, but there is no theory on crystals for plethysms of representations. To start such a theory, it suffices to solve a combinatorial problem: decompose Young's poset of partitions into symmetric chains. We review the literature, and present a strategy to do it. Our strategy recovers recently discovered counting formulas for some plethystic coefficients, and new state-of-the-art recursive formulas for some plethysms of Schur functions.