Weird technological developments that seem anachronistic aren't too unreasonable; according to one source, it took something like 750 years to go from the potter's wheel to a wheel(tire/cart) in Egypt. There's the aeolipile from ancient Rome(?) that's basically a prototype steam engine (it needed to be hooked up to something to be useful... which they never did). Risou no Himo Seikatsu did a decent job with technology I thought; they got their food section in by having the continent be reptile-based, so while they have eggs, dairy products are largely unheard of (though there are cultures that have them a long ways off).
Were they actually impressed by shovels? I may be mixing up my series here, but I thought they were impressed by the *quality* of the tools he was using in this one, which would be perfectly reasonable.