Both Lazarus and Tabitha were most certainly physically dead. Regarding Lazarus, St. John provides an awful lot of detail to make it explicit that at Jesus' words,
the dead Lazarus arose. He is clear that Lazarus was
physically dead before the words our Blessed Lord spoke to him...
Jesus explicitly tells the disciples Lazarus is most assuredly dead. --->
John 11:14
When Jesus arrives in Bethany, Lazarus had been dead and in the grave for four days. --->
John 11:17
Martha warns Jesus that because he had been dead for four days, if He opens the grave, he will stinketh. --->
John 11:39
Jesus commands the dead Lazarus to come forth. --->
John 11:43
The dead Lazarus comes forth AFTER our Lord's command. --->
John 11:44
The risen Lazarus is still covered in his burial clothes, which Jesus then orders to have removed. --->
John 11:44
Regarding Tabitha at Joppa, St. Luke too provides details to make it explicit that at St. Peter's words,
the dead Tabitha arose. He is clear that Tabitha was
physically dead before the words St. Peter spoke to her...
Tabitha was sick and died ---> Acts 9:37
When St. Peter arrives, he is brought to the grieving family of Tabitha ---> Acts 9:39
St. Peter commands the dead Tabitha to arise ---> Acts 9:40
The dead Tabitha arrises and is presented to her family ---> Acts 9:41
Were Jesus and St. Peter wrong to speak to the dead?