I just started up a 1.14.1 server, and we are setting up our spawn area to be a protected area.  We can easily prevent most mobs by typical lighting, walls, etc.  An Illager Patrol has decided to have a consistent respawn point near the center of our manually set spawn chunks (consistent as in they regularly spawn there every few in game days).  The respawn point for the Illagers is definitely over 200 blocks from the nearest village and mansion.  We are running vanilla, and don't have any obvious way to protect against these raids (besides using commands to give us iron golems), which are inside of our protected block zone (We currently have all of spawn protected so people can't randomly mess up the server ticks, etc). 

This is a VERY serious issue, as this is where new players spawn into the world, and are the least protected.  We desperately need a way to stop these raids from forming.  There is currently no in-game vanilla method to stop this from happening either via builds or by server op command.  We are early in the server set up time frame, and this is seriously hampering our ability to move forward.

I've included a map showing our designated spawn chunks (17x17) and their relationship to the nearest village and woodland mansion.