I consider myself a bit of an expert on hammer drills. I have a 20v Dewalt for personal use, and a Small Milwaukee M18 and a large corded Bosch Roto-hammer in the survey truck.
For everyday survey use, I would propose a SDS+ Hammerdrill with a high number of impacts per minute, with a low impact force. This minimizes damage if your crew touches the aluminum cap, while still dong a great job of loosening up gravel, stone, chipseal, and road tar.
Bosch makes a pocket sized carrying case that holds a mini bullpoint bit, a chisel bit, and 4 drill bits suitable for mag nail and mag spikes. If you are setting rebar, I would suggest a longer bit that matches the rebar you use.
If you are excavating roads to set Mon cases, at minimum, you need a 14Amp sdsMax Roto-Hammer, with a 40lb jackhammer preferable.
If you think a $280 drill is too expensive…. clearly your crews earn considerably less than mine. That drill paid itself off in about 3 holes.
Once you have an investment in cordless battery’s, a cordless vacuum is another very valuable tool for sucking water and debris from monument cases. Minimizing time spent working in the middle of the road is money well spent.