PPV is also usually very easy to obtain, if you have an acceptable combat force (even a frigate or cruiser for patrol), you most likely exceed the colony's PPV requirement anyways.
This depends on the scale of colony I think. My extrasolar colonies in my current game, yes - currently the biggest is under 24M and would be pacified by a single example of my 7500 ton 32 PPV 'cruiser' types easily, or by a very understrength fighter formation of just 2-3 craft.
The 417M on Europa, on the other hand, demand 142 PPV. Since they're covered by the main fleet anchored over the homeworld, that's no problem. But anywhere else I'd need to post at least 5 cruisers to keep them happy, whereas my standard squadrons to completely overkill the spoiler race problem are only 4 cruisers and I could probably shut down real incursions fine with just one or two, especially in my latest iterations of the type.
If you had a colony running into the high hundreds of millions in a place where it wasn't exposed to a real enemy attack, you might have reason to bulk out its PPV with budget-conscious options alongside a small patrol force.
But in the OP's case you...definitely might want to go for a real home fleet rather than pure showpiece ships. Not doing so can get rough.