Spurs bought seven players last summer under former boss Andre Villas-Boas - all foreign and without a minute of previous Premier League experience between them.
Only two, Vlad Chiriches and Christian Eriksen, have come anywhere near justifying Spurs's decision to buy them.
Current boss Sherwood said: "You can buy someone who's never played in the Premier League and he comes over and is a revelation but it's more of a risk doing that.
"Premier League experience for me would be key. If you want to look at any team it would have to be Everton and what they did in the transfer market was second to none.
"On deadline day they looked like an average side but all of a sudden they make three signings and it has turned them into what they are now.
"They have done very cute business.
"They were certainly the players that Martinez wanted. Gareth Barry has over 530 Premier League games which is crucial for any club.
"Lukaku was the best young players last season and had that loan spell at West Brom which was brilliant for him.
"Deulofeu, who everyone knows was in the development phase of football can be anything he possibly wants to be and he is showing that now.
"And the James McCarthy acquisition. They have certainly done brilliant in the transfer market."