Turbine engine with a primary stage of airfoils and a subsidiary stage of airfoils

A turbine engine comprising:

• an engine core defining an engine centerline;
• sets of airfoils comprising a set of part-span guide vanes and a set of fan blades, the sets of airfoils circumferentially arranged about the engine centerline, an airfoil of the sets of airfoils comprising:
• a main body portion extending chordwise between a body leading edge and a trailing edge;
• and
• a leading edge protector receiving at least a portion of the body leading edge of the main body portion, the leading edge protector extending chordwise from a protector leading edge towards the trailing edge of the main body portion to define a leading length (LL);
• wherein the main body portion and the leading edge protector together define an exterior surface of the airfoil, wherein the protector leading edge is different from and forward of the body leading edge, and wherein a chord length (CL) is defined as extending chordwise between the protector leading edge and the trailing edge of the main body portion;
• and
• wherein the LL is related to the CL by an airfoil protection factor
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• and a first APF (APF1) for the set of fan blades is different than a second APF (APF2) for the set of part-span guide vanes.