3x a week total body workouts? thats a bit much, though i did that for a couple months myself. the general consensus is 4x10 releases the greatest amount of TEST, but thats general consensus. everyone is different - 4x8 works for a lot of people. i don't know how to answer you as far as over training. are you starting to work out again doing total body workouts? if so then you know you have to start at 1x a week for the first week, 2x a week for weeks 2 & 3, then 3x a week on weeks 4 and beyond. for total body i assume you're doing a variation of the 300 workout (5x10 with 6 exercises)
if you're not doing isolation, you can do this type of stuff. if you are isolating, twice a week is the most for any body part. i need more info to advise better.
when i was doing the 300 workout (3x a week) i noticed i had to do variations like the following or i wouldn't progress in weight or size.
M - squat (ass to ground) / bench / deadlift / pull up / floor wiper / clean and press (5x10)
W - lunges / push ups / floor wipers / DB curl to arnold press / deadlift with hex bar (6x10)
F - DB bench / sumo deadlift / chin ups / dips / floor wipers / the sled (5x10)
anyways, PM me if i'm not answering your question properly - and good luck. hope this helps. on a related note, post workout you need protein and carbs for isolation, but ONLY protein for a 300 style workout. 5x10 is a natural test booster for sure, but you're relying on more free GH in your system to burn fat and gain size on this kind of thing, and high carbs supresses natural GH levels, and the test boost is more of a secondary bonus - pretty much the opposite of isolation exercises, where test is key, and GH is secondary if it matters at all....