You can parallel multiple chargers but they need to be compatible for maximum charging. For example I have 3 chargers for my batteries: solar, alternator and charger (with gen running) and while this works OK they may not be 100% compatible. And solar is the only one with a remote voltage sense probe on the house battery.
However, I recommend that you buy a MPPT controlled that is designed for parallel connections with a single controler. ie They are connected by a small data cable with a single point of control.