Errors is less of a concern. Fans get obsessed about errors and fielding percentage, but the flaws with both are well documented. Fangraphs rate the Cubs team defense at 12th last year, and 5th the previous two seasons. Honestly, without comparing personnel across the board, it would be difficult to know whether Maddon has a problem there, but the overall numbers suggest he doesn’t.
But even there, raw error totals tell us jack about defensive strategy, etc. That is what is actually relevant.
Base running, per Fangraphs, had the Cubs mid league the last two seasons, and above the Angels this season and behind them the year before. Outs on the basepath could mean they had really aggressive base runners or base coaches. Hard to know with the bare data. Still, in both areas, I think he’s at least as good as Ausmus and probably better.