It was late yesterday for me, sorry if I said weird things...
I read cacti-integrate.php to understand what it does so I'm ok with it.
What is not easy for me now is that I'm talking about Cacti & Weathermap as memories (I used them couple years ago - as you can see I don't post often but I'm registered since...2006 ^^).
I don't have a server right now but I'm going to install it in few days so I try to imagine how I will use it...so you can understand it's not easy for me

So if I use Cacti, the Cisco template will generate all relevant informations about me devices' ports (as far as I remember).
When I'm going to create my weathermap config file, I will write a perl script to generate all ports for my Cisco N5K (6 devices with 500 ports each)
Let's say first card has 2 ports, second has 16 ports, third has 48 ports, fourth as 16 ports.
So I want my script to create an image with 4 cards (or FEX). The first one will have only 2 ports (with color red/green), the second will have 16...
I guess I need to use an image with 48 ports for all cards an only fill 2 ports on first, 16 on second....right ?
How my script will know that first card has two ports ? What is the information in Cacti that help me to make the difference between my cards (the Interface Name / Descr ? How will my script gather this information).
Other possibility - in my case no graph is needed (only UP/DOWN ports), so I was thinking about not using Cacti.
I mean, I can gather all ports states and description in a simple MySQL table and then generate my weathermap config file (in this case I know how to easily parse interface name so I know how many card I have). Don't you think it would be better ?
And...I don't agree with you - Cacti and Wearthermap are so smart !!! So far I didn't find any competitor which could stand in front of weathermap...