Agree but shouldn't be too hard to fix. 1 ohm balancing resistor means 1mA current imbalance assuming 1mV offset while adding 20mV output voltage variation over 20mA load. Maybe that's fine?
Or gang together 3 opamps with balancing resistors and use the 4th opamp to regulate their output (cascade costs some bandwidth).
But yes, buying an appropriate buffer amplifier may be the best choice. Be careful with opamp current specs too, many specify typical output current, not minimum.