How Fittig reaction gives good yield if phenyl cations are unstable? I am confused,after reading from NCERT text that phenyl cations are unstable due several reasons like the carbon in phenyl group is sp2 hybridized,resonance structures do not stabilizes the phenyl cation.But then,in Fittig reaction we do have phenyl cations as intermediate.For example in a reaction between two molecules of chloro benzene and sodium metal we get a diphenyl molecule.Here we have two phenyl cation generated (if i am right).Then what factor stabilizes the phenyl cation?If there is any error in the theoretical aspect of the question please help me correct it as i am not quite sure about the mechanism.

I would be very much glad to accept an answer with some thermodynamical data like the bond enthalpies of C-Cl bond and newly formed product's bond enthalpy that is C-C bond enthalpy(in the case of diphenyl)and the total realease in energy.
The most probable mechanism for Wurtz reaction or Fittig reaction involves formation of organic free radicals and not cations. Like in Wurtz reaction, phenyl free radicals are formed in Fittig too.