Why not design starship must phaser weapon lot more powerful

[Jason 27]

Ship used to portal protect Earth convey ships not design have must power to defense systems. They doing long range mission NX Enterprise. We saw the NX Enterprise be able to deliver set phaser to overload able blast right though shields of enemy starship slight enemy.

 

I can think of three possible

1. NX Enterprise generation lot more power then any other starships order get up to warp 5 drive. First civilian starship using a warp 3 drives. Military at least had warp three drive. NX Enterprise will able to produce something like little less 10 times the power that warp three drive produce. Problem this theory first each phaser cannon fire times design for 10 times.  NX Enterprise did not have power issues. Even was power issue still explain for simple reason. Matter more that get though shields then amount phaser cannons one can fire at a time.  

2. The amount power it require to be transformed to phaser cannons.  Again we can practice terms control that type power today at least thoery Orion proct run H bombs require able control more power fact did do today mean can not. Talk control Fussiah give power of H bomb it little sense do the research if we could control the power it out getting overload. Yes likley require upgrade power systems power relays. That another story not something to hard to do.

3.They already doing it but ships so action expansive were not upgrade yet.Very possible starfleet comamnd was more or less take it time. Depend number shipyard have available everything else.

I be interest other possible reasons