Tactics for playing as the Dwarves.

My entire gaming experience boils down to completing campaigns, so I can't claim to be an experienced player, but it seems to me that investing in Light magic for Dwarves is unnecessary, as Runes and Light magic practically duplicate each other. Runes offer resurrection, dispel magic, and punishing strike, just like Light magic. What Dwarves lack is a unit that can effectively counter archers, which is why the Blindness spell was very useful. Of course, you can use the Fire Wall spell for priests against archers, but I think Blindness will be more useful because you can break out of the fire, but there might not be enough time for a second attack from the priests.

Most importantly, all the effects of Runes and Light magic spells are cumulative. Try applying the Dragon Form Rune and Punishing Strike to Jarls/Earls. The damage will be extremely high. The same applies to resurrection. If you really want to, you can first resurrect with a Rune and then with the hero. Bears with the Energy Rune can successfully counter archers (but it depends on the map). And for the Blindness spell you're talking about, you need Darkness magic. But where do you get the spells? And it's not a given that you'll find it. In general... I advise you to read the last few posts in this thread; I think they clearly and concisely describe when and which magic is best to take and why.