Yeah, better in many ways to halve the number of trolls (to 28) and give 2 of these trolls (the leaders) 6 unassociated levels of cleric so that by the time the party has blasted through the main group of trolls they will have to face the 2 clerics buffed by divine favour, bull's strength and protection from fire.
Lower EL but higher threat.
Semi rant time about 1st edition adventure design
Sure, sometimes it's nice as a player to have your 9th level fighter with (in 1st edition terms) gauntlets of ogre power, a +3 weapon and 3 attacks every 2 rounds, to be able to easily take down a large number of foes that even at 6th level, when you were relying on your 17 strength, your +2 weapon and your 1 attack per round, were enough to challange and possibly kill you in a one to one fight.
But... if you look at some of these early adventures these encounters are not going to occur once every 4-5 game sessions but will almost certainly occur every single session - quite possibly 2 or 3 times in the same session. Even back in the 1st edition days I found these encounters to be a horrible waste of time, both as a GM and when I was playing.
3.5 edition may not be perfect but (IMHO at least) its emphasis on having (mostly)appropriate challanges for the character's level is a big improvement over these type of time wasting encounters
