It's best to workout every day. This helps to establish a habit of regular exercise.
DAREBEE programs are designed with "active recovery" days, meaning some days the work load will be easier and/or focus on a different body part. So your body gets the recovery time it needs to keep getting stronger without burning out, but you don't have any days of doing nothing.
See this guide and this one for more details on the benefits of active recovery and training every day.
Active recovery is already built into The Gauntlet (and all other DAREBEE programs). They're designed such that you will reap maximum benefit from doing the program every day. There's no need to alternate program days with anything else.
If you simply don't want to do the program every day, that's a different matter entirely. The best program for you is the one you will stick with and do every day. So if you're saying you'd get bored with doing kettlebell workouts every day, so you want to alternate, this is fine. But the non-kettlebell workout days aren't your recovery days. They're cross-training days. And you'd need to set up your own schedule.
The Gauntlet by itself has a 5-day cycle:
Day 1: legs
Day 2: upper body
Day 3: core
Day 4: upper body
Day 5: functional fitness (emphasis on full-body coordination, endurance, cardiovascular strength, tendon strength)
So your proposed training cycle would be 10 days long, and you'd choose workout activities for the non-kettlebell days that complimented the kettlebell workouts you do on either side of each day.