"Death by a thousand cuts" appears to be the main tactic in play right now.
The rules for a Federal reduction-in-force are very complicated and require 60 days notice to the affected employees. The lawsuits and temporary injunctions forbidding the actions could easily take much longer than that to resolve. It can be done quickly - and has been done before (c.f. USGS shortly after the Oklahoma City bombings). But not this time. There are too many Obama-era judges who are willing to rule against anything that President Trump may do to the Civil Service.
Regrettably, the top-level managers in the Senior Executive Service ranks are exempt from the actions and would be the very last ones to be removed from any department.
But anticipation of the event can often be more stressful than the final occurrence - and may cause greater behavioral changes.
Putting pressure on employees of the FBI, Justice Department, and Homeland Security looks like a fairly clear strategy. Those organizations have engaged in unlawful and seditions actions against the President. Decimating their ranks would be appropriate. Prosecution and jail for a great many of their executives would be well-deserved, although likely out of reach.
Not so clear what the point may be of pressuring the staff in the Department of Interior, the FDA, or the FAA. I would have believed that HHS and the Department of Education would have been better targets. Perhaps the better targets had already managed to secure their funding before the selection started.