Older home (1947) , 2 story home (3 including basement) on a conventional foundation. Basement measures close to that of a single car garage, ceiling is open to floor joist of 1st floor, 3 foot opening to remainder of 1st floor footprint. Home is approximate 2500 sq foot. Imagine a hole 12 deep 15x15 with the remainder of the crawl space 3 foot headroom for the remaining home footprint. 5 air vents 2 foot above ground level spaceD around perimeter of home. Home is rectangle shape.
This is a rental house, a nicer property with a cost basis of a tad better than 300k I am using to generate income for the foreseeable future.
Would like to be prudent while also maintaining the value of property.

1) how many exhaust fans would you use to “pull the air” through the space
2) would you place them on same side of house, or opposite sides
3) what size of motor would you have paired with your fan
4) if I am looking past or forgetting any other best practice for long term solution

I will appreciate any input, thank you.