Weight downward on a pole is not a problem. Figuring worst case of about 600 lb./sq.in (NTS-1991) for wood, bearing on 1000 lb./sq.ft. soil (UBC, IBC); weight, even with XF's, cap's, etc. is well supported.
Resistance to overturning (lateral resistance) is a big deal. Wind load, seismic motion, and conductor tension are the factors, and must be calculated based on location (wind & seismic), soil type, and other factors that our engineers just snowed me with when I asked.
POCO's have standards that are well overdesigned for their areas and equipment, and are the closest to "rules-of-thumb" around.