Power System Neutral Earthing

From the picture there is two type of earthing system, solidly earthed system on 0.4/11kV step up transformer from diesel generator while low resistance earthed system for 10MW & 15MW generator to 11kV distribution system, if for some reason all the 1.6MW diesel generator are not running and only 10 and 15MW generator are running, i was told that the earthing system for 11kV distribution system will change from solidly earthed to low resistance earthed which will reduced/relay the operation of earth fault current protection in the 11kV distribution system.

My question is, if this is the existing system what is the best solution should i do to overcome this problem? Thanks