If you run Amrath wilderness lowly trogs will give you str and con stat damage. I use a cheap inexpensive lesser restore pots to get rid of it. I mostly run as a FvS or a ranger; FvS is easy in that sense. Unlimited cure light, blade barrier and the odd searing light to finishing off a low HP target.
But it's always that much 'easier' to move down critters and bosses with my ranger. 2 con op items, the new epic cloak of night, one vorpal for almost all stuff and a construct beater for the siege golems and such.
The point is that I can do anything a caster can. It's just a matter of having the right resources to do it. Some stuff is going to be a lot easier; say a caster in some wilderness and quests. Like my FvS and rainbow in the dark. Less then 30 minute stomp with maybe a little tougher in the end. Not so much with my ranger due to having to carry the light source.
But it's the opposite with running with the devils. Here DPS is king. It's very hard to out DPS and kite the eladrins. And that I guess is the whole point; some solutions are easier. Others are tougher, but you'll notice more than often that end game quests (above 16) are usually oriented around maximum DPS and less finesse and magic.