First I set the crank timing mark on TDC, then I set the intake cam on TDC and tighten the three gear bolts using the spanner wrench to hold it in place. With the exhaust gear in place but the three bolts hand tight I install the timing belt then release the tensioner and loosen the three bolts. The tensioner should take up all slack in the belt. When you see that the belt is slack free, tighten the three exhaust gear bolts. I just tighten the exhaust gear up last to equalize the timing belt tension. If the belt went on with the gears on the timing marks, it should work OK when the tension gets equalized.
I hope this helps with your tension.
RK