pritch

I want to put better shocks on my emaxx but I'm a bit short on cash atm so I bought 4 stiffer springs instead as a stop-gap. Now I know a lot of people run different rated springs on the four outermost shocks to the four innermost. I would have thought this variation would have placed stress on the arms? What different set-ups are made available by running a mixture in this way? Atm I'm really considering putting the four +20% stiffer springs on all 4 rear shocks as I'm suffering uphill from excessive squat, but I'd like to hear opinions. Using 40ht oil btw, and I don't want to go thicker than that on the stocks.