“Is it wise to send new converts out into the battlefield before they are grounded in the Word and apologetics?”
It is the best thing you can do for them. The woman at the well didn’t go to a seminary before she testified of the Savior, and she brought a whole village to Him (see John 4:28–42). After finding Christ, Andrew immediately told Simon Peter (see John 1:40,41). The first thing Philip did was find Nathanael and immediately tell him about the Savior (see John 1:43–46). If new converts came to Christ under the sound of the Law, they know enough to go and do likewise with the lost. They will make mistakes. They may get bruised. But that is how we learned to walk in this life, and the same is true spiritually.
Luke 10:3Go your way; behold, I send you out as lambs among wolves.