The states impact all battlers. The HP bars script just displays each instance of a state separately (it displays "ATK Lv1" twice instead of "ATK Lv2"). You should be able to fix that by changing line 139-142 of the HP bar script:
@battler.states.each do |state|
@hp_bar.draw_icon(state.icon_index,xx,yy)
xx += 24
end
=>
@battler.state_icons.each do |icon_index|
@hp_bar.draw_icon(icon_index,xx,yy)
xx += 24
end