Couldnt faculty just slow down work, or do other things short of a strike?
No – There are legal restrictions on work actions we cannot simply withhold grades or fail to perform other work. Such things would count as illegal work stoppages, and anyone who did them could be disciplined or fired for not doing their job. If the union declares a strike (after following all the proper legal procedures, including filing a strike plan), then that kind of work stoppage is legal, and faculty will have legal protections against retaliation or firing. Even in a legally authorized strike there are unconventional actions which are not permissible. For example, striking workers are not allowed to picket the residences or businesses of elected officials of governing bodies. Nor may we engage in unconventional strikes such as sitdown, slowdown, rolling, intermittent or on-and-off again strikes.