Well, that's just me, but I think the card system is ok.
The whole purpose of the system is the RNG and the lore of the role has everything to do with it.

My guess is that people want the best combos all the time and I don't think they are wrong, but we have to remember that every card is positive in a way.

Like the example of the OP: If you had a NIN, a DRG, a MCH or a BRD, you wasted all your cooldowns trying to get rid of a spear that would be SUPER useful. More useful than an arrow, which would drain the TP of everyone above. Spear would even be good for other classes with short CDs.

I believe that we have to deal with the RNG throwing every buff the best way we can and AS FAST as we can. (Not that I don't use shuffle, but I use 1-2 times in a raid) This way, we can guarantee that someone will be buffed and we will not waste time looking for the "perfect buff" that might never come...