Work on your weakness or play to your strength. The balance of Natural Fitness versus Natural Differences.

The concept of general physical preparedness has become trendy in relatively recent times as part of the functional fitness mantra connected to ancestral fitness and military readiness doctrines. So systems such as CrossFit and MovNat both call for us to work on our weaknesses to develop a well balanced capacity for dealing with any physical situation.

This is good summary of the premise: crossfit-functional-vs-natural
 General Physical Preparedness (GPP) – or “being ready for anything.” CrossFit argued that its program trained initiates for the “unknown and unknowable.” 

A key part of this model is that you need to find your weakness and work on it to round out your overall GPP. MovNat also advocate development of all your movement abilities to achieve a holistic movement capacity, and emphasise focusing on any weakness.

I have always had a bit of an issue with the "work on your weakness" concept. I am fully aware of the anti specialisation position of both CrossFit and MovNat, but check out these "many different variations of the human physique" in  athlete-body-types-comparison

Yes, this is an extreme and striking illustration of my point. But even in a tribal situation where all members are well balanced in natural fitness, or a military unit where they all get the same training - there are natural differences. I reckon that yes, we should minimise our Achilles heels, but the real focus should be on what you do best. 

Rafe Kelly's recent blog on this topic matches my thinking in this regard; 

"We should all be generally capable, but we are all equipped also with different inherent talents and drives. The natural 250-pounder who loves lifting heavy things should of course still be able to run, vault, climb, and move on the floor but if he spends a bit more time on moving heavy things his whole community can benefit from that great strength. On the other hand, if he focused solely on becoming the perfectly balanced athlete that neither his natural constitution nor personal play personality reflected, he would likely never develop his full potential in total capacity or in his joy of movement. Similarly, a lanky bouncy athlete who loves to dance should certainly invest in some heavy weight training to balance his strengths, but trying to make sure his manipulative capacities were as developed as his dance would be overkill in my opinion".
 So if someone is in the situation where they are thinking "I need to eat more to get bigger so I can move more weight and compete with those other big guys", maybe they should tweak that into "I will get myself stronger to balance my structure/abilities more, and also to feed my strength at X, which I can develop further naturally and use as my 'superstrength' ". Like Rafe says - "add what is uniquely your own".  Find your own balance of Natural Fitness versus Natural Differences.