Ground Fault Circuit Interrupter vs AFCI
What can happen...

If you look closely at the way many AFCIs behave, they will trip on a gross ground fault. This is no accident; instead, they rely on this behavior to catch arcs-to-ground specifically (it's the same reason IEC systems use RCD protection panelwide).  The converse of that is that an arc-to-ground will trip a GFCI as well. This is one reason why Ground Fault Protection of Equipment (GFPE) is called for by certain parts of the NEC -- GFPE devices are like GFCIs, only with a higher trip threshold (30mA or 100mA vs. the 6-10mA of a GFCI), and are only seen in breaker form due to their limited scope of usage.

But, you still need AFCI

However, the discussion above does not cover arcs between hot and neutral.  These arcs will not trip a GFCI or a regular breaker, since they simply bypass the normal load path at a level too low for a normal breaker to trip on, and are why AFCIs were originally developed.  These use electronics to "listen" for the broadband radio-frequency signature (snap crackle pop) created by arcs, and distinguish harmless arcs (from switching action, hot-plugging of receptacles, light-bulb burnouts, or the commutating of motor brushes) from hazardous ones.