In no source can I find a reference to C. perfringens leading to slow-onset diarrhea. I just did an AMBOSS question that mentions it leading to diarrhea within 24 hours. AMBOSS back this up, as does cdc.gov; NCBI statpearls actually says onset 8-16 hrs. As such, if mentioning all bacteria generally that can lead to diarrhea via spore ingestion, it’s perfringens, B. cereus, and C. diff.