Does it require the same delta-v to reach the same heliocentric orbit that Mars has as it does to reach Mars? Ignoring entering Mars' atmosphere, is the difference only timing of the launch?
Your question hinges on what you mean by "reach Mars". Trans-Mars injection takes you to Mars' orbit, and if your timing is right, takes you close to Mars.
Mars orbit insertion is a separate maneuver, executed close to Mars, which leaves you in orbit around Mars. Without the orbit insertion, you will fly by Mars at about 4800 m/s without stopping. To get into orbit around Mars, you have to do both.
(Besides aerocapture, there's also a trick called ballistic capture which can achieve a very high and barely-stable orbit around your destination without an insertion burn, but it's not useful in itself for planetary exploration.)