You want cogent political philosophy from a Scifi writer?
Well, in this special case: Hell no!
Generally, I don't see a point in expecting that experts in political philosophies will come up with something new or visionary. The impossible will always be created by the dreamers and naive. Those who don't know to fail yet. And if this dream convinces some of those experts, they will come up with a less crude philosophy, that will become less impossible. And when most people are convinced of this dream, the political theory has become political reality.
But, maybe we are just misunderstanding each other there, so here my point of view: Heinlein wasn't really a political genius or especially secretive of his own believes in his works - he made his figures speak for him and if a figure didn't want to fit into his views, he punished it so long until it realized that its creator was right. And he also wasn't a subtle writer at all.
And still: Heinlein noticed pretty correctly in Starship Troopers, where Engels took the wrong turn. Of course, he still got it wrong himself in the end. But he noticed the weak spot. And little surprising, the weak spot actually is the connecting thread in all of Engels later works. What Engels saw as liberation of the working class, was actually its enslavement by the capitalist class:
Yeah, this one's for the workers who toil night and day
By hand and by brain to earn your pay
Who for centuries long past for no more than your bread
Have bled for your countries and counted your dead
In the factories and mills, in the shipyards and mines
We've often been told to keep up with the times
For our skills are not needed, they've streamlined the job
And with sliderule and stopwatch our pride they have robbed
The same egalitarian idea of Engels, that skills and special knowledge shouldn't be mandatory for a job and people should never be considered better or more valuable by others only because of the skills and knowledge they have gained in the past, actually was making the workers just an expendable and easily replaceable resource for the owning percent of the world. And with improving technology, even the lower management is today endangered of getting their jobs streamlined. Followed by middle management and eventually the upper management - until the point, that there will be only owners and owned.
There is no difference in communist and capitalist vision there and both are a working class hell. In both cases, we will never own anything. Not even our job. The only difference will be who owns our lives and who will profit from our lost pride.