I think it’s pretty common & easy for a daily-weekly rebalance strategy pair-trading US equities to achieve ~1.5 sharpe for a few years after fee. There’s a tons of paper on this. But in practice now people do it on a basket against another basket, and securities are not limited to US equities
i guess it’s very limited, in established firms people have proprietary backtesting and simulation engines. you can implement your own tho (which is not difficult), but imo the biggest challenge is data. most paper either do not open source the code or do not share the data