Early aggression

Since my childhood I was always playing HOMM with the same style, turtling up, completely upgrading my castle, massing army and leveling up main hero, but lately I tried early aggression on small map against Vanir on worthy difficulty and had blast, completely dumpstered him with Rana's wielder who gets +1 dmg for hunters without waiting too long like I usually do.

What are the best faction and wielder for ultra agressive playstyle? Does this strategy only works on small maps and 1 vs 1? Thanks.