You can make any bike shimmy,depends on how you load it.

Try shooting an arrow backwards,everyone knows the heavy part likes to be in front,same with bicycles.Hang a 10# weight,10ft of the back of your bike and let us know how it handles

The more weight you can put in front/down low,the less chance of shimmy,simple physics.The heavier the back of the bike,the more it wants to be in front.

In a perfect world,our panniers would be under the bottom bracket.But since there's not room for them there on most bikes,we must compromise.For the best handling,the rear load should be as low as possible and as far forward as possible.On the front,the load should be as low as possible,and centered with the front hub as possible.Centering on the hub decreases the effect of the extra weight being thrown around either foward/behind the axle.Adding weight in front/behind the front axle adds the FEEL of more/less caster angle(trail for bike people) depending.Weight in front of the axle will make it feel heavier/sluggish because you are actually lifting the weight as you turn,weight behind the axle makes it feel lighter/snappy,because the weight is helping you turn.

All of that said,your still adding weight to the ends of the bike,so it's never going to feel like a "regular" bike,no matter how it's made.

My poor old Shogun gets 60-70% of the weight in front.Sleeping bag,tent,water,anything heavy,goes in the front.Clothes,kitchen,food in the back,and the lightest/bulkiest sleeping pad and tent poles on the top of the back rack.