The FCC has basically zero capacity to actively monitor the number of transmitters programmed for a given frequency overall. They could, in theory, determine the number of active transmitters in use at a given time, but I have never heard of a public safety agency or member being fined for being overlimit on transmitters. Overpower, sure. Cursing etc, happens all the time; but I have never even heard a story of an agency being fined or disciplined for having 152 radios on a 150 unit license. The purpose of specifying a number of authorized transmitters is too charge appropriate licensing fees. Don't get me wrong, the technology exists, it would just be a pointless endeavor the overwhelming majority of the time.
Programming many radios, most notably Motorola, requires licensed software and strongly encourages licensed cabling. You can get bootleg software that may work and may brick your radio. Bootleg cables may work, but OFTEN brick radios. This is usually worth the risk when you're talking about obsolete radios, as paying a radio shop to program something like an HT1250 will cost as much as the radio is worth, everytime; but is a terrible idea when you're talking about a current radio. Current radios(P25, dual/multi band, Bluetooth, encryption etc) cost thousands of dollars. That's a huge gamble on an eBay cable.
I've owned and programmed my own radios for both amateur and public safety purposes for pushing twenty years. I've done it with factory software and cables, commercial knockoffs and homebrews. I've bricked a few, saved thousands on programming fees, and always had a radio I know works. This doesn't matter so much at my current job, as my issued radio far exceeds my best personal; but was a big deal when I worked for crappy privates who didn't think having a portable radio was required.
One option for you could be a hybrid idea. Ask your superior if you were to assume all associated costs and have the programming done by a licensed technician/shop, would they officially authorize you to acquire a personal radio. This is the exact mechanism I used to acquire my first radio. I paid for it, sent it to the towns contracted shop for programming, and it was totally legal. When I left the agency, I could have had the programming wiped and kept the radio, but I ended up selling it to the agency instead.
When you work for an agency that gives you the tools you need to do the job they're asking you to do, it's easy to say "that's your bosses responsibility". It's different when you're dealing with low budget organizations just trying to keep fuel in the tanks and paychecks covered. I'm not personally going to castigate you for having the idea. Just keep it legal and authorized.