One group does da'wah in the UK and warns against the big schoolars like shaykh sulayman ar ruhaylee and salih suhaymee. One if this hroup doesnt warns against them. Is it allowed to take knowledge from him? Even when he is doing dawah with the group who warns against everybody

Ustadh AbdulAziz al-Haqqan

If he isn't upon their way, why is he with them? And without a doubt he would praise them etc, therefore he should be avoided along with them as he takes the same ruling as them as is known from the way of the salaf.