Even if SL struggled with 70mph trundlers in rainy old Vardyville, there are precisely zero relevant takeaways from getting destroyed by Tom Wells (beyond 'be less **** and hit the ****ing red thing') when it comes to preparing for Anderson at Lord's.
At least if they'd played vaguely comparable opposition that are closer to the standard they'd be playing in the Tests -- and still got equally demolished -- at least they'd get more relevant information.
It's not just about adjusting to conditions, its also about adjusting to the standard of opposition. SL could play 25 games in the lead-up against league teams or 2nd XIs and would probably still get killed in the Tests, because facing sixteen versions of Rob Taylor doesn't give you much meaningful preparation when you've got Broad at the top of his mark in the real stuff.
I can't blame England, or the counties, given how much they need to manage workloads. But wouldn't it be better for both English cricket more broadly and SL's preparation if they had, say, an attack of Barker, Roland-Jones, Plunkett, and an Overton brother all fired up trying to force themselves into England contention?