Why the late start for Var?

Okay, after doing some research on what a lot of users are doing for their cycle stacks, I've seen something that seems to be a recurring thing and i haven't found the answer as to why.
I'm going to be starting my 5th cycle soon which will consist of Test E400, Tren E200, and Anavar 50mg/pill. I've done the Tren/Test/Mast combo before and have used just Test/Tren before, but I haven't ever experimented with Anavar before. I've seen this cycle pretty frequently used among lifters who want to increase lean mass and strength, but it seems they always start out on week 4-6 depending on the actual length of the cycle, and I'm just curious as to why? Why not run it the whole 10 or 12 weeks? I am venturing to guess it has to do with liver toxicity which would make sense but wouldn't a good detox and liver supp do the trick to combat this? Thanks in advance for any info. Also, I already have everything on hand for the cycle including Nolva, Clomid, and Prami for on-cycle support and for PCT. My BFP has always been low so I haven't needed an AI in the past but I do have a personal source close by that I could easily get Adex from should the need arise.

Why run adex when problems occur? Its used to prevent problems occurring in the first place so is recommended to use during the full cycle.
You cant jump out of a plane without a parachute and just order one before you hit the ground, its too late.

Why are you running nolva and clomid for on cycle support?

Run your AI and HCG and Liv52 or NAC for on cycle support.

Ive heard of people running var 8-10 weeks max. Most orals are toxic, plus the cost for anavar may be an influence.

Me personaly, id run it for 8 weeks

I understand what an AI is used for, I've just never had need of one so far so I saw no need to jump the gun and get it when I already have it readily available to me if needed.
And I didn't mean I was using nolva/clomid for on cycle support, I was speaking in general for the Prami for while on cycle to combat prolactin from the Tren and I said nolva/clomid for PCT. sorry if I worded that strangely.
But okay I gotcha, thanks for your opinion. You would run it for 8 weeks max, so if I'm doing a 12 week cycle then you suggest starting at week 4?

Its personal choice, some prefer kick starting their cycle with orals, some prefer back loading.

I prefer using at the end, so yes if i was doing your cycle id prefer to start it at week 4. And if the 50mg anavar was going wel id be tempted to increase the dose half way through the 8 weeks of anavar. Like 50mg for 4 weeks then like 70mg for the other 4 weeks. Not that this is required but id be tempted :)

I wouldn't bother with bar if you are running tren over 200mg per week. In fact, my summer cutting cycle will be tren @100-150mg per week so I can add var. low dose tren keeps all sides away and actually gives me really good results.

Var @10 weeks is my preferred length.

Get an AI and run it, you only know you don't need one if you are getting mid cycle bloodwork. There is no guarantee your source will permanently have stock of anything. Always have everything you do, or might, need before you cycle.

I appreciate the info guys, thanks. Started pinning last night so we'll see how this one goes.