Identical hides are important because in the wild, ball pythons have a variety of hides to choose from and this allows them to thermo regulate. In captivity, we can't offer them that. Ball pythons WILL sacrifice being at the proper temp for security. If they favor one hide over the other, they will stay in that one, which means they could become sick from not thermo regulating. Make sense?
To the OP. I would suggest getting a thermostat now. Dimmers are a quick fix while you wait for a thermostat to arrive in the mail (since you can't really find them in stores). With a dimmer, you will have to constantly check the temp and adjust the dimmer switch. With a thermostat, you set it once and then you never have to worry about a temp spike.