Why restrict yourself to massing only 1/2 types of ship when your fleet is quickly growing and replacing at that time? The abundance ship hulls are dispersed into different types and methods, and good deals are by random chances with no guarantee that ship is exactly what you desire. They are hard to source individually and intentionally without visiting many markets for many months, unless you do commission and gain a new market access to faction hulls, or hunting and salvage from certain factions and their deserters. You can't consistently pick 2 hulls from bounty until the difficulty quickly rises to capital stack after a few bounties. Plus earlier frigates on that received S-Mod continue to serve well into late game for catching smaller ships and capping points. And S-modded ships are the best bang for the DP used.
Pirate hulls that I would keep for utilities are those with shielded cargo holds, the highest being a buffalo. For combat hull it grew from shrike, manticore | colossus, eradicator, falcon | atlas. Most of them are missile rich and DP lean for its class. As you can see there is no good (P) frigates and they are usually store bought or pristine sensor-package salvage exotic high tech frigates. frigates are needed for auto resolve chase battles.
Enforcer shines latter as bigger ships gets slower that their heavy firepower and armor become useful, before that they are trailing behind and can't contribute much of the fight against hull of its size or lower.