The dog is the gatekeeper of Iporo,
Agbo, the ram, is the gatekeeper of Momo.
Ewure, the goat, is the gatekeeper of those who cannot keep their mouth shut!
Momo is the gate between heaven and earth- this is the heaven of the ancestors and the orisa. So what I find interesting is of course the ram. Heimdallr is the sentry at the bridge, the crossing between earth and valhalla. Some people, myself included, see his post as more than just being a sentry to valhalla, he decides who gets to go to what is often considered a higher plane. In the verse above, the gatekeeper is the judge, here it is the ram, whose full name is Agbo Momo, who decides who gets to go to the heaven of Momo.
My own gnosis is that this is much of the reason behind Heimdallr's silence when it comes to many people, he isn't social. This allows for more impartiality. Just a thought and may not be correct. But yes, I do firmly feel he is the final decision maker as to if a human, at death, goes to a different plane. Even Odin and Freya, they may choose a soul, but Heimdallr has to put his stamp of approval on their ass! YMMV.