Paralleling MOSFET Oscillation
There are 3 connection paths between 2 parallel FETs. You might think of them as 0 Ohms but every conductor has resistance and inductance and if near another insulated conductor automatically has some capacitance.  The semiconductor dielectric also has capacitance and it gets bigger with smaller RdsOn.  So in choosing a part with smallest gate capacitance, one will see that some parts have a lower and higher RC product from the normal distribution depending on the internal design of the FET. 

The impedances are thus treated as 3 miniature transmission lines with inductance of ~ 0.5nH/mm and the output and junction capacitances lumped together in datasheets ; Coss,Ciss that are derived from Cds, Cgd, Cgs.

If you re-read the article, it tells you how that gets transformed into a Colpitt's Oscillator.  It also gets worse when Vt thresholds are mismatched. The oscillations  can be prevented by choosing a suitable low gate resistor for each gate.   The article shows where these ringing problems can occur during switching. 







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