The official boards don't supply nearly enough ground and power pins. I put 4-5 each on all my microcontroller breakout boards.
Just wire as many connections as you want to the same pin. Or take a wire from the ground pin and connect that to as many places as you want.
Love your avatar. So I can just fit them all in the same ground hole on my UNO?
but you are only gonna get one pin in that 'hole'
Or, how big your hole is?