Each 2N4401 needs it's own 220 ohm resistor to allow current sharing amongst all of them. With a single 220 ohm resistor one of the 2N4401 would likely be dominant and the others would be starved of base current. There is less than 1/10 watt dissipated in the 220 ohm resistor, so it doesn't have to be any larger than 1/8 watt.
If the range is inadequate, try replacing one or both emitter LEDs with TSAL6100. They are narrow angle, so the range will be extended due to the more focused beam. (More of a spot light rather than flood light).
If you want to make the whole device smaller, then use a single RCR123A or CR123A battery instead of 3 x AA.
Adding more transistors and LEDs to the circuit would probably not be very effective due to the limited current available from T1.




