Without knowing the specific reactants and conditions of the reactions you are considering, it is not possible for me to accurately predict the type of substitution mechanism or compare the expected rates of the reactions.
In general, the type of substitution mechanism that occurs in a given reaction depends on a variety of factors, including the nature of the reactants, the solvent, and the temperature and concentration of the reactants. The rate of a reaction can also be influenced by these factors, as well as by the presence of catalysts or other substances that may affect the rate of the reaction.
To identify the mechanism of each reaction and compare the rates of the reactions, you would need to consider these factors and use information about the reactants and conditions of the reactions to make predictions about the mechanisms and rates. You could then use this information to draw the organic products of the reactions and compare the expected rates.