That make sense. Now that I think about it, there must be a function of weight, suspension, etc that must be all balanced together as well as the front and rear.
That's it exactly.
IMHO, you want a front sway bar especially with a swing-axle, because the snap-oversteer baked in the cake with a rear-engine, swing-axle car should be the one thing you are thinking about all the time. A front sway bar induces the tendency to understeer (to some degree)-- which is an excellent way to keep from oversteering.
To clarify regarding rear sway bars-- swing axle cars do not run a rear sway bar, as they already struggle with oversteer. What is needed in a swing axle car is some way to limit positive camber (the "wheel tuck" graphically shown in the pictures above). Swing axle cars run limit straps or camber compensator bars to help keep this from happening, at least to some degree. Lowering a swing-axle car will also set the ride height in such a way as to increase negative camber under normal conditions, which gives you more suspension travel before the camber goes positive (and tries to kill you).
I'd not run a swing-axle car without a front sway bar and a camber compensator, but I'm just a pansy that way. Regardless of how well my friend Mitch can write about it, I'd rather dance with an IRS car than negotiate with a swing-axle.