This. Especially if you are playing Ranger Rogue which obliges you to plan truly accordingly, so you won't waste a lot of gold on resetting skills or traits. Powerful bows are really hard to obtain, so you may want to rely on your companion, either Grissenda or Hirge, to protect you on your quest for powerful bows. Once you get yourself Massive Critical and Precision Shots, you become so OP that you can literally spend most of Ancient Tolassian Tome's trait points to your companion to make them tougher.
Anyway, here's my own point of view for classes in Exiled Kingdoms:
Rogue is probably the hardest, the most difficult, class to start with as it requires some proper plannings and patience. But Rogue deals the most damage to enemies, either with dagger, bow, short sword, or axe, especially dagger or bow. The other thing about Rogue is how good it is in dungeon as it can not only detect traps and secret doors, but also disarm traps. Personal note: I also found Rogue to be the most fun class to play as, either as Silent Assassin, Ranger, or Trap Master.
Mage is also difficult as it also needs thorough planning, and Mana can be a problem, but once you have finished around 40-50% of your build, and has finished one of your companion's quest, you are unstoppable unless your enemies managed to defeat your companion, overwhelmed you with numbers, and had their level at least 4-5 below you, especially above hou. And now you can play Mage with close-range weapon, which is exciting for those who like making and planning builds. Personal note: I play a Summoner, specifically Iron Golem, and Iron Golem kills every enemies for me, along with Grissenda. I kinda regret not having Ranger Adaon though.
Cleric is so damn OP from early to finished build. Sure, it may not be as tanky as Tank Warrior and not as powerful as Assassin Rogue, but Battle Prayer is so OP that it can turn even Adaon into a tank. Mana is not even that much of a problem for Cleric, unlike Mage. The only thing that would keep it down would be how limited Cleric's equipment is compared even to Mage. Personal Note: Haven't tried 2-Hands Weapons for Cleric, but even just 1-Hand with Massive Critical can deal enough damage to powerful non-Undead enemies like Sabercat Alpha, Hill Giant, or Warg.
Warrior is simply the best choice for any beginners. You can focus on offense, focus on defense, or focus on both, and all of them are great, though it's still up to your preference. The best thing about Warrior is how wide its variety of both weapons and armors; Warrior can wield the strongest weapon and the most durable armor. Personal note: If you go offense, Massive Critical and Precision Strikes are must-have skills for your build, and then Duel. I'm trying a full defense build, and damn, is it tough!
The best Class? There's no best class, just the best personal build for each class. But Cleric and Warrior are probably the best choice for those who are rather new to the game.