Multi-million dollar missile vs. my $139.99 dollar GPS I hope so.
Still, even if they had the same in accuracy would still be good enough to destroy a HAS with fighter aircraft inside.
No doubt that military equipment is much better but it is more than that — sounds like the Tomahawk is very sophisticated. What they should do is stick a camera on the end of it so that targeting can be changed on the fly. Then again, targeting is probably done from satellites or awac. The question: how accurate is the targeting information — targets move? This is why surprise was so important in Syria.
Also, with the drones flying all over in the states, a terrorist could weaponized one and deliver it with high precision. As you point out, even the lesser precision commercial GPS systems are still adequate. Something to be concerned about.