By 1969, they were way better than the Beatles.
And they did not have the Wrecking Crew play on their albums. In fact, if someone was lucky they had, say, Larry Graham or Greg Errico play on their records.
Unfortunately, Sly stopped using them so much.
What about Sly & the Family Stone?
Hell, yeah! They started the whole funk movement, that bands like Parliament/Funkadelic in the 70s. You can definitely hear their influence on Prince as well.
And IMHO their set was the best one at Woodstock.