Doesn't help that some new players who don't bother reading the descriptions will keep spamming Fire2 on single target or constantly Blizzard3 and Fire3ing. Thankfully they're rare cases, but I have a feeling the [spell+number] is partly to blame. People can say that Fira and Firaga are confusing, but I'd say the same argument can be used for all the samurai+ninja skills with foreign names that make no sense to me as a non-JP speaker (or anime watcher).