That's one way to go. Maybe try this.
You keep moving, yes. But not to get "not surrounded". You always attack, evade, attack. You take away THEIR space, not the other way around.You will be in a "target rich environment" while they will be dealing with a narrow, always forward angling, moving target. You herd THEM together, from the second the instructor yells GO,
My guess is you'll first line up with the three of them lined up opposite you. Try this drill ahead of time. Get three of your workout buddies line up opposite you. When you say go, everyone WALKS three steps. They all step towards you, to trap you, to get you.( Doesn't matter if they would or not, it's part of a learning process.) You walk three steps as well, angling forward to the outside of either end man. You should be in a position, relative to theirs, where one is shielding the other two from getting to you in a straight line.
You walk through this several times, always slightly different because they'll be adjusting too, and you start to learn angles used to impede their ability to get to you en-mass. You IMMEDIATELY attack the one closest to you, trying to force him to step back, further taking their space and cramping their kicking distance, their timing and their foolish game plan of attacking YOU.
When you practice that drill, try your first step with alternating feet. Find which foot first allows you to land in your best offensive position after three steps. Then start practicing at different distances apart, taking note which foot on odd and even steps.
If you take it to them from the git go, and never ever let up, nor slow down, you will take them so out of their game you'll own them.
Another drill, this for your vision - in case they do surround you, or you start that way in the test.
Stand about ten feet in front of your buddy. Stare into each others face.
Behind you have two assistants, about ten steps back, about five feet to each side of you.
Keep starring into your buddy's face while the assistants slowly take small steps straight ahead (in step). (If they were to reach you they would be five feet to each side of you)
When your peripheral vision picks them up, YELL STOP. Now, look around, take note how close up they were on either side.
Repeat the drill. Except, this time, focus your eyes about a foot in front of you on the floor. Have the assistants repeat their steps. Yell stop again. Take note how much quicker your peripheral picked them up. How much farther they were away. Looking down lowers your "cone of vision". Cone refers to the basic shape of your field of vision. Lowering it, taking out the sky portion, increases how far the edge of the cone behind extends behind. Good for multiples.
There's more, but I'll leave you with this. With multiples, attitude is everything. If you don't think you can beat multiples the prophecy will be self fulfilling. And you NEVER fight for ties. No "I'll take out as many as I can before they get me". That is the attitude of defeat. If you KNOW you can beat multiples, you will beat them every single time.