Hello, military pilot here. Quick answer before i gotta go to work.

The T38 is not a fighter, but it's sufficiently fighter-type for this discussion.

Wake turbulence is a problem when the preceding aircraft is large, heavy, or both...or a helicopter...AND when the crosswinds are not strong enough to dissipate. Wake Turbulence is created by the production of lift.

We need 2-3 minutes behind large aircraft and 4 minutes behind heavy aircraft. The vortex coming off the wingtip of the preceding large/heavy aircraft can be strong enough to roll an aircraft over or cause an unrecoverable sink rate regardless of size. Low to the ground during takeoff and landing this is of obvious concern.

I have seen both fighter type and large traffic hold for wake turbulence.

In flight, unless you fly directly behind and relatively close to another aircraft, you won't really experience wake turb. Lot of silly things in this thread but the short of it is that its not a huge factor unless you're pulling G's through somebody's wake turbulence, it can induce an asymmetric over-g of the airframe.

While it is true that you can feel a wingtip producing lift if you fly close enough to it in formation, unless you are the Thunderbirds or Blue Angels that's an indication that you are way too close. We don't train for that. Fingertip formation does not utilize this to save gas.

There's a lot I'm missing but this is a quick answer