I really like the idea.  I wrote up a "Greyhawk Fire Department" years ago, using 1st level or so characters, but thinking through ideas on what magic items the city could provide and how low level mages could be useful, that sort of thing.  4th level is pretty buff compared to what I think should be normal, but for a SWAT team, it makes sense.
I advise you to think SWAT -- special weapons and tactics. A ranseur or guisarme fits in the SWAT category, but some of the equipment in the PHB is directly lifted from a modern SWAT arsenal -- Thunderstones, Smokesticks, and Tanglefoot Bags. And SWAT units are famous for snipers -- think poison arrows, Sleep Arrows, Bane heavy crossbow bolts with poison on them, all fired from a Holy bow.
Other reasonable equipment to have available (perhaps in a locker back in HQ until needed, rather than counting it against each NPC's equipment list) are various Protection and Resist Energy potions, plus potions like Invisibility and Cat's Grace.
Yup, I like the idea of an Invisible min-maxed sniper with 19 Dex using a Holy heavy crossbow to fire a Human Bane bolt with Wyvern Poison, Drow Poison, or Black Lotus Extract on it. Excellent, Smithers.
				
			I advise you to think SWAT -- special weapons and tactics. A ranseur or guisarme fits in the SWAT category, but some of the equipment in the PHB is directly lifted from a modern SWAT arsenal -- Thunderstones, Smokesticks, and Tanglefoot Bags. And SWAT units are famous for snipers -- think poison arrows, Sleep Arrows, Bane heavy crossbow bolts with poison on them, all fired from a Holy bow.
Other reasonable equipment to have available (perhaps in a locker back in HQ until needed, rather than counting it against each NPC's equipment list) are various Protection and Resist Energy potions, plus potions like Invisibility and Cat's Grace.
Yup, I like the idea of an Invisible min-maxed sniper with 19 Dex using a Holy heavy crossbow to fire a Human Bane bolt with Wyvern Poison, Drow Poison, or Black Lotus Extract on it. Excellent, Smithers.