If there's a major factory in your district that produces AC/5 class autocannons, you're probably going to vote in favor of that new design with twin AC/5s, as opposed to the "distinguished gentleman with the stupid idea" across the aisle who wants to put in dual LLs on account of a factory in his own district producing those. The military has called for a PPC-equipped design, but that doesn't have any support from the parliament or ruling council, so the military will just have to figure out how to use what they're given instead.
Real world examples include the US Army listing 12 military bases for possible closure back in the 1990s, which it claimed served absolutely no strategic purpose. All 12 were in the districts of influential congressmen, and ultimately only 4 bases were closed, NONE of them from the list. Politics and profit are far more powerful motivating factors than effectiveness when it comes to military hardware, which many of the original BT designs reflect. Yes, they DO make sense, but not necessarily from a purely military perspective, and especially not when you're comparing specialist units of various types to "line" units for their suitability at front-line combat in close quarters.
"The design was a major success, despite its significant flaws, as the senator who submitted the bill for its purchase in quantity by the House Military was re-elected."
