Thank you for your interesting email regarding the relatively 'open' stance as found throughout the various lineages of Fujian White Crane Fist when practicing the 'San Zhan' (三戦) or 'Three Battles' Form - as compared with the 'closed' stance work (and obvious groin protection) found within the 'Sanchin' Kata of the Goju Ryu Karate-Do Style!
Yes - I have noticed this. I was talking to a student about this. It reminded me of the stance used for skiing. As if 'gripping' or 'stabilising' on a slippery surface. Sometimes, the old Masters (such as Master Chan) would talk about stepping in, through or onto congealed blood - which is slippery. He fought, wounded and killed invading Japanese soldiers during WWII (1941-1945) as part of the Hakka Resistance operating throughout the New Territories (a People's Militia had developed - supplied from the Mainland). His father (Chan Yun-Fat) was killed fighting in 1944 leading an attack on an Imperial Japanese Army position - armed only with traditional gongfu weapons. This was a diversionary attack whilst those armed with the limited number of rifles and ammunition attacked the main target.
His wife's mother was gang-raped by Japanese soldiers, skinned, hung-up by her hair and set fire to. Por Por (Mrs Chan) used to tell us stories for years about those terrible times - until her passing in 2011 (years later, a Detective contacted Mrs Chan and said one of her brothers had survived a Japanese village massacre and had been taken to Australia by foreigners - she got to meet him again one more time in his now native Australia a year before he passed away. I spoke to him on the telephone. He was around five years old at the time of him going 'missing' - with his small body being hidden under the bodies of the adults killed around him).
We practice falling to the ground forward, backwards and to the sides in our Hakka Longfist Family lineage - and using Ground Fighting (with a groin guard and a head guard). I suspect that other aspects of the Fujian Style in question also teach a groin guard in an accumulative sense - as is usual in traditional gongfu. Goju Ryu is highly rationalised and modernised (a process of sheer genius) - which is a good thing - but traditional gongfu is often sprawling, illogical and difficult to fathom!
PS: Wong Tai Sin is our 'Daoist' family God - as Master Chan Tin Sang (1924-1923) was a TCM Doctor (taught in the old way). It is virtually impossible to acquire statues of this 'healing' God as it is very carefully guarded by the Temple Authorities in the New Territories! We have a photograph on our family shrine - but my ex-wife currently looks after the family Wong Tai Sin statue (which was passed into my keeping by Mrs Chan upon her passing). Indeed, my ex-wife can be seen on the above-linked BBC programme - 'Escape to the Country' with our family statue of Wong Tai Sin (黃初平) shown at 5:39:
Shifu Adrian Chan-Wyles (b. 1967) - Lineage (Generational) Inheritor of the Ch'an Dao Hakka Gongfu System.