Well, I thought we were talking SFB (& SFC).
That link is to a fan-tech site and uses data from some semi-official specs listed in more recently done things like the "Starship Spotter" or the older Mastercom or Jackill data sheets. It's all fine and dandy, but it's not SFC. I bet EVERY Fed ship has P-3s once the General War hits stride, or Phaser-Gs in their place. In SFB/SFC. Which is the game we play.
One of the things that made SFB X-ships interesting was the way the phaser-1 had several uses - standard, overloaded, as "gatling" phasers. The superior point defense option was taken out in SFC, probably too messy game-wise, so they came up with the "phaser G2" in OP for X-ship point defense.
As far as labs go, in SFB/C a Fed CA has 8 labs, a GSC 10, NCLs 4, FF 2. The original DD also had 8 lab, but that's the ship that couldn't walk and chew gum, so 4 labs were replaced with APR, making it a nicer thing to be stuck in battle with. Mostly across the board, other races ships had fewer labs. In Trek, well, they don't really say. I "think" I remember Spock saying something about 7 labs on Enterprise but I'm not sure, and don't feel like walking upstairs to my library to comfirm that. Same with transporters - they never really say how many on the show, although maybe someone calls up from "Tranporter Room 4" in some episode.
I just think it's worth repeating - SFC comes from SFB, and SFB was wriiten before a huge chunk of Trek was created. Things like labs or transporters that have a game function have been set up a certain way for balance, as Lt Q suggests, and changing them changes balance. Believe me, many suggestions have been made to the makers of SFB that go "I saw on an TNG episode where..." or "the Klingons had these weapons in this movie..." or "these blueprints show...", and these suggestions are Shot. Down. Immediately. They do no have the license to put those things in, they can't get the rights to, it changes the game "flavor," and most importantly, They Do Not Want To. It's someone else's sandbox that has some things from Trek and then a lot that's not. Sorta like the JJ movies, it's a different timeline.
So, if you want to make a Enterprise like another source has it, have at it. I've done a couple myself, it's fun. But some things will affect game play, that's all. Like the Police ship I made with 12 Phaser 4s and 30 warp. It was fun to fly, but not really fair...
Of course, another work-around for the refitted 1701 is in the "Spotter" - 12 RIM12C Phasers & 6 RSM14B Phasers. Make the "RIM12" P-1, and the "RSM14" Phaser 3. Makes it X-ship level without making it a BB. Just don't tell Keiron.