I would say that amount used for a first cycle, should be more dependant on the level youve managed to achieve so far. In every drug you take you seem to have limits on what your body can deal with, your question is test, if your dosing is high, your more likely to get aromatisation effects etc, There are only a limited amount of receptors in your body (albeit alot) and as taking AAS will usually shut down production of your natural test anyway, as well as down regulating the receptors over continuous use. (Digressing slightly) No in answer to your question, If you can imagine taking say 500mg of exogenous test, in both the low and the high natural ends, the low (assuming the natural test isnt shut down quickly), would be 520mg and the high maybe 600mg (per week),
A bigger more muscular person doesnt necceserily have more test, its more likely that they are either,
genetically more gifted,
lift according to what works best for him,
has a higher calorific intake, different ratio in diet, protein fat etc, types of food and how easily assimilated the protein is,
sleep,
The list really does go on and on, keep a first cycle simple, dont work with silly doses in the hope that youl put on more, work with test if you like and go nuts with the training and eating, I promise if you and your friend are doing the same amount, he has the higher nat test or whatever, you will do best to really increase the protein and carbs keeping it clean, and try looking forward to your next workout.