I don't think PB says no Pike. Like all other fish they have to be managed correctly or you can have problems.
GShad can cause problems as they get to large for most all predators. What size are the GShad that you see ? Also GShad if not greatly suppressed by predation can deplete the plankton supply and also suppress reproduction by other species. It is not uncommon for GShad if out of control to take over a pond and fill up a large part of the biomass. To control a GShad population with LMB you will need a high % of LMB over 18 inches + and even then it can be a challenge.
Large pike can help but it would be good to not have a breeding population of them in the pond.
Is this what you have - large northern GShad ?



Some possible options other than rotenone are gill nets or electrofishing deployed by fisheries scientists.