Short answer: it can't be done. Giving pikes a secondary weapon line other than zero enables the sword, regardless of the characteristics assigned to it.

'Fixed' pikes are an abomination. I've acknowledged that many times. But unfixed pikes are, well, lame, which is worse in my book. As I have stated before, the primary aim of the 'fix' was to get the pikes to, well, actually use their pikes. Balancing and all that were purely secondary concerns. Munchkinism? Who cares? Don't like it, don't use it.