Pesachim 65: The Bloody Pageantry of the Korban Pesach

Finishing the 5th chapter: On the third group of the Korban Pesach, which was called the "lazy group" (but doesn't the Gemara stipulate that there are 3 groups? How is it fair to knock the third one??). The world is built to contain the range of professions, both males and females, and more, but some of those are praised and others denigrated (cough, female, cough). Namely, the third group had to exist, but that doesn't make it ideal. Also: A mixture of the blood on the floor would be collected and sprinkled on the altar. But, asks the Gemara, isn't there a halakhic issue with not collecting blood immediately upon shechitah? Apparently, the kohanim were again vigilant, and in their eagerness, managed to spill, apparently regularly. And isn't that blood a halakhic barrier, blocking the feet of the kohanim from the floor? (Not as wet). The service of God via animal sacrifice is a bit foreign, but perhaps no less profound because of it.