They should just dump it and tax dividends and capitals gains like any other income.
It's easy to shift corporation tax but much harder to shift an individuals income.
It's much easier to simply impose an AMT and eliminate a relative handful of expense shifting mechanisms (many of which are already covered by a regime known as "transfer pricing").
I think that even if taxing corporations doesn't make sense in terms of tax revenue, it makes sense in terms of stopping companies from growing too large
Imo corp tax should be nil until you get to about 1m profit, and then brutally progressive after that. Small businesses are great, and companies that benefit the consumer by being large can be public-owned and both compete internally and internationally.