what we really have to sacrifice is the goat of ignorance (Goat faced dakshan represents that).

But at lower level (people who have not attained inner maturity) sacrifice other beings for their wishes to fullfill. There again it is not just any goat that you sacrifice. You should sacrifice some thing that you love very much. Even in Islamic tradition that is the intention to sacrifice the goat.

Sacrifice is to part with something that we hold on to it. Holding on - or attachment is the apsect of ego and so a small practice to give up that ego is to sacrificve. Over time it is mis-interpreted.

So tell the devotees to sacrifce the inner goat of ignorance instead of killing an animal.

When the inner goat is sacrificed , the life of one becomes so good and prosperous.

As a pujari you have the responsibility of removing the ignorance of the devotees and you become the middleman between God and the devotee. All that you do should help the narrow the bridge between God and devotees.