One solution to show pet tier is to use symbols -- similar to how orb levels are shown.
tier 1 = 1 dot
tier 2 = 2 dots
tier 3 = 3 dots
tier 4 = 1 diamond
tier 7 = 1 four-point star
tier 10 = 1 five-point star
tier 13 = 1 six-point star
etc
If need be, you could color code them. Set 1 (the first 15 tiers) is black, set 2 is silver, set 3 is gold.
These could be placed beneath the pets for party members; and for the player's pets, they can go anywhere adjacent to the pet.
tier 1 = 1 dot
tier 2 = 2 dots
tier 3 = 3 dots
tier 4 = 1 diamond
tier 7 = 1 four-point star
tier 10 = 1 five-point star
tier 13 = 1 six-point star
etc
If need be, you could color code them. Set 1 (the first 15 tiers) is black, set 2 is silver, set 3 is gold.
These could be placed beneath the pets for party members; and for the player's pets, they can go anywhere adjacent to the pet.