API 650 5.10.4.7 a states '...If an unstiffened horizontal plate is designed to distribute the load, it shall have a
nominal thickness of not less than 12 mm (1/2 in.). Alternatively, the column load may be distributed by an
assembly of structural beams. The plate or members shall be designed to distribute the load without exceeding
allowable stresses prescribed in 5.10.3.1.'.
Apparently, the base plate thickness is in the range of 5 mm ..and does not seem to be stiffened .(for thin base plate , no.of brackets should be at least eight ). However the total thickness of wear plates seems thick enough to distribute the load..That should be confirmed with calculation..