As some of you may have noticed, Orpheus wasn't listed in the first line of the family grid. Instead, he appeared alongside my four other current PvP pets of choice. (Kalypso is taking it easy; she is still a bit of a hermit crab.) This was partly a reflection of how organized I keep my stable, as those five are generally the ones with me, and the other four rows appeared in the usual order of my deep stable.
The other major reason I chose to display them that way is because they are a team, moreso than any of my other pets. Generally, my pets either run with me as a duo or as part of a larger raid group; there are a select few cases of pairing off (Atalanta and Hippomenes, Perseus and Andromeda, and the twins Castor and Pollux), but they are fewer and further between.
Last night, I was able to cycle through all five pets multiple times against a druid-warlock team. None of them died, since I kept switching them after they were dotted up. Orpheus and Arachne especially got into trading off in multiple matches.
If only I had three more stable slots, I would gladly run with five spiders. This is really fun!