A way of getting better comparisons might be to look at the clauses of the components and finding a way to reliably reduce the size of clauses, perhaps in a similar way as is already being done for statements (e.g. re-running the dependency parser on the clause or re-interpreting the clausal relations).
This could help produce smaller, but still descriptive, clauses which which provide another point of comparison between components, i.e. when comparing variations in the size of compounds using a long or short clause might provide different results.
A way of getting better comparisons might be to look at the clauses of the components and finding a way to reliably reduce the size of clauses, perhaps in a similar way as is already being done for statements (e.g. re-running the dependency parser on the clause or re-interpreting the clausal relations).
This could help produce smaller, but still descriptive, clauses which which provide another point of comparison between components, i.e. when comparing variations in the size of compounds using a long or short clause might provide different results.