If you are catching tench and catching carp with what you deem strange hook holds , this could be a good thing. It seems to me by the snippets of info , that you are instantly hooking the fish as soon as the hook enters the mouth. I don't know you're full set up rig wise., but one thing for sure is you are hooking them. A rig I use , I use it purposefully for this very reason . I accidentally catch some very hard to catch, very sort after tench. As well as catching carp. Some hook hold s are in the top of the mouth . This is tench and carp. I use short stiff rigs with a small soft braid hinge, in conjunction with a size 6 mugga.
Anglers have varied opinions on hook shapes , barbed and barbless. At the end of the day , our intentions as anglers are to impale these metal components in to our chosen quarry. Bent hooks were to serve a purpose, I used them myself at the time to good effect . Size 6 drennan lure hooks were my choice at the time. Hook holds were savage.
Jim gibbinsons line aligner article was to explain the extra effectiveness that piercing rig tube had when the carp had the hook in its mouth . Thus making the rig more efficient.in making the hook turn into the bottom lip.Some 25 years later has stood the test of time.