There are so many things that affect operating EER, SEER & BTUH that this listed matching stuff, IMO in this situation may be way overrated.
Make sure there is plenty of airflow for a 4-Ton system, many don't have adequate ductwork systems to fully support 4-tons of cooling.
It may deliver better airflow with two 500-sq.in. each filter racks exterior to the air handler. Use two low pressure loss filters & don't let them load to much.
In that Houston heat, make that evaporator coil & condenser work somewhere near their Rated capacities to the indoor temp you select, & you'll be a cool dude. Under heavy indoor load conditions, if its not too hot outside, condensers can eject heat well above 48,000-BTUH.
If it gets too horribly hot outside, with a heavy indoor load, you could, if deemed necessary, block of some of the return airflow.
Have your tech look up the free air area of the SA diffusers & multiply the FPM velocity times that to get the CFM. CFM times 30 will Ball-Park the BTUH of each branch run.
Air is king in air conditioning. Whether its a listed match may be rather inconsequential. Many Mfg'ers just use it to bug out of warranties. - Darrell