the community has a deep concern on how protoss can survive early aggression without super battery
why not just make available for more than one battery to heal one unit?
the balance team can set a upper limit as to how many batteries can heal the same unit at a time, or
they can set the healing efficiency to be marginal diminishing (1 + 1 is less than 2 , i think the second battery can provide 25% higher shield restoration would be good enough) or the second battery has a less efficient energy-shield restoration rate (which might make it more powerful than the original super battery, but the energy would be used up very quickly)
but there should be a default setting that each battery would automatically heal one unit that means protoss player have to manually mirco the batteries to heal a particular unit
actually, i think mass SCV repairing should have a similar treatment 