The knights get outranged by the disruptors or pinned by the placeholder and jack'd, the ronin get pinned by the placeholder and toasted or jack'd. Should I do glaives? worker cloaking field for the knights? Fac switch (but to what?)?

Reavers are usually a better protection for ronin than knights are. The main strength of knight is in tanking damage, which doesn't really come into play when defending other units. Reaver will stop raiders like pyro and will do better vs jack as well. Placeholder you do probably need imps or phantoms to snipe. Glaive would also have been a good idea to try just to raid or to harass the moderators into a more clustered position. A conjuror with its cloaking field active or an iris plus imps or reavers can then wreak havoc.

Just beware that moderators high alpha plus high slow damage will destroy shields quickly because slow damage (and emp damage) is converted into damage against them.