Oil consumption in cars usually occurs when rings go weak .. rings act as a seal for the piston but when they wear this sealing effect reduces and oil from chamber (lower portion) mixes up in the cylinder area (with air and fuel) and burns causing smoke
light foot or heavy foot .. with weak rings oil will burn
My brother in law has a vitz 2003 model with more than 250k km on odometer and still original engine is good .. a toyota engine (1000cc category) can last up to 400-500 kkm if kept with care and timely maintenance
An overhauled engine do good only if machining work is done properly, mechanic is good and uses all precautions as per manual and finally the parts r of good quality .. i would say overhauling is an equal gamble