Pressure testing is crucial to any MA that prides itself on being a "fighting system".
There is simply no way around it.
Now, there are different types of pressure testing of course, ranging from light contact to full contact and same-system testing to cross-system testing.
It have been my experience that the more specialized a system is ( take southern mantis or wing chun for example) the more cross- system testing they require.
Why?
A few reasons but basically because the same-system testing is far to limited in those cases.
Allow me an example:
Boxing is all same-system testing of course, BUT because it is so natural and "easy to learn" because it is natural, the carry-over into real life scenarios and VS other systems works well enough.
The issue is with a specialized system, like WC, the carry over is less because it is NOT as "natural" as boxing.
Anyone that has done both knows exactly what I mean.
So, WC to be effective VS a different system needs to be pressure tested outside itself more.
This does NOT mean one stops doing WC, it means that the skill set developed when one trains WC VS WC needs to be developed differently to be used in WC VS BJJ or WC VS MMA or WC VS Muay Thai for example.
So, those clips of WC VS Xingi and other clips of WC VS other systems will have a very different look then any clip of WC VS WC and that is a GOOD thing.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !