I have a feeling that you actually don’t need a Hashtable / Dictionary. An ordinary List will do.
You need to import the System.Collections.Generic namespace at the top of your script in order to use the generic List.
// UnityScript
var player1deck = new List.<Transform>();
A List allows adding and removing of elements but behaves like an ordinary array.
player1deck.Add(T1);
player1deck.Add(T2);
player1deck.Add(T3);
print(player1deck.Count); // prints "3"
print(player1deck[0].name); // T1
print(player1deck[1].name); // T2
print(player1deck[2].name); // T3
player1deck.Remove(T2);
print(player1deck[0].name); // T1
print(player1deck[1].name); // T3
print(player1deck[2].name); // ERROR since there are only 2 elements in the list
player1deck.RemoveAt(0); // removes the first(index 0) element
print(player1deck.Count); // prints "1"