We are at different ends of the spectrum when it comes to 'fight' with fish. I use my Spey rod for everything including grayling and seldom stray below an 8 or 10 pound leader. So.....with that said not all places will accommodate a 13' 9" rod and when I fish small water (usually in fall) I fish with a #5 rod 7' 9" long.
I have caught some very large fish on the 5 weight but do not target big fish on light rods. Even when using the 5 weight I keep an 8 or 10 pound line out there that way should I get mixed up with a good silver or large trout I am good to go. Rods will handle more than we may expect when it comes to landing a fish. However, you must exercise caution in how you handle the rod when you have a load on it. For instance, don't even think about bracing the rod a foot or so above the cork when you've got a big fish bending the shafts. This is a sure path to snapping a bottom section.
What it really comes down to is the leader, if you are fishing a 5 or 6 X leader and hook into a Chum chances are it'll bust the fly off. Conversely, if you are fishing 8 pound because you are expecting a chance of a big fish the rod will land the fish provided you handle things well. What I said at the beginning about different ends of the spectrum was reference to the fact that I prefer to land fish expediently. The longer the tug of war the better the chance of the hook pulling loose. Also, having a light line attached to a big fish may allow the fish to get the line into sweepers or God knows what. Because of that and that i wish to land what grabs my files I use heavy rods and lines. It is my own opinion that catching a grayling or other fish in the 12 - 17 inch size is just as enjoyable with the big rod as any other way. I don't see landing a fish as fighting the fish. I see it as a matter of having a proved method of getting fish to the shore soon as I can. This is especially true when I am C& fishing because to use light tackle because I might enjoy feeling the fish fighting for its life on the hook is not something I have enjoyed ever since I began to catch a lot of fish. I figure that the faster I can land them, the more I might be able to catch. When you haul them in, they either come to shore or come loose, one or the other. Many large fish will challenge your ability at landing them regardless of what your plans may be but continued practice at getting it done will be of great importance.
I hope you will take that as what it is; my way of doing things. I know that there are many people who love the light tackle thing but unless I'm in a creek where I would never expect to get hold of a real bruiser I use the big game rods. Trust me, you can feel even a 10" char struggling even on a big rod. What you don't have to worry about is the fish breaking off
Where are you at here,