philebus
As a player, I tend to think in terms of function in play. We can understand the trumps as symbols or as a theme. Any pack of Top Trumps requires a theme to work but I would hesitate to call the cards symbols - we could do of course, and rightly but that is not their function in the game and whatever a Tyranosaur may symbolize in some context, that is probably not the reason for its inclusion. For the game of tarot, the pictures on the trumps had to meet two requirements: 1) they had to differentiate from the regular suits - including the courts. 2) they had to lend to indicating the card order, as numbers were not printed. If the figures of triumph processions were familiar, at least to the original players, and they had a familiar order, then this would be enough for the choice to be a good one, without any regard to what individual figures might symbolize in a religious context.