I have my ROTH IRA through Charles Schwab. I am 28. My investments are currently 50/50 between SWPPX and SWYJX. I am considering changing it to 80% VTI and 20% VXUS. Or should I just go 100% into SWYJX? Also, does the target retirement date really matter at this point if I am between 2055 and 2060?