Lineup Help - what to do with Peterson, Burkhead, and Richardson

Roster so far 12 team .5 ppt:
QB: T Brady
RB1: C McCaffrey
RB2: ?
WR1: D Funchess
WR2: D Thomas
TE: C Brate
Flex: ?
DP: J Bosa
DP: R Jones
K: M Bryant

P Richardson, A Peterson, R Burkhead to fill in the gaps. Also considering Starting A Shaheen over C Brate.