I would maintain that the level of accuracy to be competitive at either silhouette OR schuetzen is high and that a lot of the difference in who shoots either or both has to do with personality and attitude rather than the intrinsic shooting capability required for each.
I personally shoot more schuetzen for a couple of reasons, first and foremost is the more leisurely and sociable pace of the schuetzen game. ASSRA was born from a growth in interest in getting together and shooting and discussing and swapping the single shot cartridge rifles that were inappropriate at Friendship but held interest for many of the same folks. Second, I personally do not enjoy cleaning BP and all the extra effort I need to put into preparation and shooting of BP...this is strictly a personal bias and has nothing to do with the sport of BPCS, it's just me, but I would suspect some others feel this way as well.
If I have any complaint about the whole BPCS game, which I have dabbled with and watched from afar, it is the artificial limits that have been placed on it as far as "legal" rifles (Borchardt no, Stevens 44 1/2 yes, for instance) and other of the arbitrary rules that to me at least have no purpose but to place some limit on otherwise suitable and historically relevant rifles and equipment. Does ASSRA do the same thing with schuetzen? You betcha! How about the barrel length rule that seems to have been put into place specifically to exclude the T-C carbines, or allowing current custom race guns but excluding historically correct single shot schuetzen bolt action rifles? Both sports reside in somewhat glassy houses!
I would be remiss in not saying that once I get to a BPCS match I totally enjoy hearing the big bangs, seeing and smelling the smoke, and hearing the clang as a distant ram or seeing the pirouette of a "tiny" chicken being hit. (This is especially true on the rare occasions when I am actually the one hitting several of the ferrous beasts!!) That doesn't make up totally for the extra prep time before and cleaning time after compared to my schuetzen participation, but I don't deny that they are a lot of fun and I do attend and join in with the BPCS crowd when time and resources permit.
BTW, if you schuetzen guys think you are so hot as offhand shooters, fall by a silhouette range and try to clean a bank of chickens with your pet offhand rifle...I think you will find the experience humbling; and you silhouette shooters, I'm sure the actual scoring of the hits that you have come to expect will be revealing to you...that 25 ring is TINY at 200 yds!
In summary, good shooting is good shooting and tastes differ as to what constitutes fun for a shooter, but these two single shot disciplines have much to recommend them and we all can enjoy both or either one individually as our personal inclinations dictate. Let's just shoot more of something!
Longwindedly yours for more and better shooting,
the Green Frog
PS And I still like the 405 gr Lyman mould 457193 for an all around 45-70 bullet on steel or paper!