Aerow: I believe you are very wrong on your assessment of Tafari. Maybe you're just not using him correctly. Although it's obvious that Hide is a warning sign for Ambush, there are ways that you can set up a Hide+Ambush combo without the enemy being able to evade it (watching/manipulating the enemy's Energy, in particular)-- in other words, trapping them. Also, you forgot about Higashi (who is almost entirely Physical in attacks)-- pulling a Tafari out against a Higashi is almost a sure win if you know what you're doing. Bottom line: Tafari is a powerful and well-balanced card as is.
Easy way to get the card: 3 warriors (in front row), 1 ranger in back row. Highest difficulty with all difficulty settings on. Explore every non-monster tile on Floor 1 that you can, and battle a couple of weak groups of enemies. Go to Floor 2 and do the same. All in all, takes about 10 minutes.