The kinetics and equilibrium of adsorption of two competing species of end-adsorbing polymer chains are considered as a model system for study of competitive adsorption processes in commercially relevant colloidal stabilizers. Two typical situations are considered invasion of an existing layer by shorter chains with a similar end group, and invasion by chains of the same length with a more strongly-adsorbing end group. It is shown that the short-chain invaders readily adsorb in the presence of an existing layer and lead to enhanced desorption of the original chains. Invading chains with stronger stickers are not effective in quickly displacing the original layer.