roebuck, hornless river deer
獐 centers on a specific kind of deer: a roebuck or hornless river deer. The meanings are narrow and refer to the same animal.
獐 combines the animal radical 犭 with 章, which likely provides the sound. The character was created to name a specific deer species.
The animal radical 犭 hints at a creature, and 章 (badge or chapter) can be imagined as a distinctive mark. Picture a hornless deer with a badge-like pattern on its coat: that's the roebuck 獐.
For ショウ, imagine a show where a trained roebuck performs: show -> ショウ, and the deer takes a bow.