To my recollection, the Intrepid class is a simple downsized Galaxy class.
Identical offensive/defensive systems with a slight advantage of size going to the Galaxy class because it can house much more torpedoes in comparison to an Intrepid and can obviously hold more crew-members.
I wouldn't be surprised if both end up as matched up in the end in terms of fire-power.
In Intrepid's defense (by having issues with a very old Klingon K-Tinga) I have to remind people that a galaxy class Enterprise-D (flagship no less) had serious issues battling a measly BOP (Generations anyone?) and eventually wound up destroyed.
Both instances of battling Klingons were potential messed up writing aspects (which we know are the culprit) ... but at the same time, Klingons aren't idiotic, and if anything, there is a possibility they would upgrade their old K-Tinga ship as time went on to keep up ... plus who knows what types of techs they discovered along their own journey which helped them upgrade their weapons (And by their nature, they would focus more on weapons compared to defensive systems).