Maybe like how combining 2 rings goes? I would like that, too.
If too OP for others, i'd suggest having weaker versions of all tackles, and only make those able to combine.
Or do you mean stacking same kind of tackles for space?
Or maybe to increase uses, like one with 1 use left, combine with another with 5, then have 1 tackle with 6 uses.
That last one wouldn't be OP, it would be more QoL that way.
If just for space, and only unused ones, i can see how that would be QoL indeed.