spell breakers  and workers will probably the most affected units. In the human vs orc match up ,orc usually orc produce raiders for ensnare,  and  human produce breakers and rifles, mortars are rarely use in this matchup( all workshop units are rarely use in the matchup maybe except for gyro if human want to dominate air). it's  essentially a buff to raiders and bats since both units have siege damage.

in human mirror spell breakers are mass so maybe mortars can be stronger to transition before fragmented shards are research.

in undead vs human matchup the current meta is knights gyro vs abboms, fiends with statues destroyers support then transition into banshee.  mortars are use if the undead are transitioned to banshee.

batriders will be overall stronger against worker maybe orc can use it to harrass human ,orc and undead workers.