If they screw in easily by hand you should not be concerned. A very lite wrenching might raise a frisson of anxiety but if it goes easily with a finger or two assisting the wrench I would not be concerned. Thread incompatibility will manifest with marked increase in resistance within 2-3 turns. Just don't over torque it at the end, those bolts can stretch and break, especially older low grade crank fixers. There is some variance in head hex sizes which can cause interference when the head goes into the crank puller thread area as you need a socket wrench to tighten and if the hex head is too large the socket wrench has no clearance. This is uncommon but I have experienced it.
Steve