For example, if you pay Securitron Squadron’s squad cost three times, then you’ll create three token copies of Securitron Squadron when its squad ability resolves. Each of those tokens will enter the battlefield simultaneously. When they enter, their last abilities will each trigger three times (once for each of the other two tokens, and once for itself.) If the original Securitron Squadron is still on the battlefield, its last ability will trigger three times as well. After all of the triggered abilities resolve, each of the three token copies of Securitron Squadron will have four +1/+1 counters on it.