I agree, you need to series in at least pairs. Can you fit an 8th panel? 7 is a tough number being a prime, 6 or 8 allows a few options, 7 does not. All in parallel comes out to 68 amps. That is a lot of current, especially at just 41 volts. You would need to run 3 full runs of #10 or #8 wire. Is the shading predictable? Will some panels never be shaded while others will always have shade pass across? Panels that are in series should see the same shading at the same time. If one is shaded, and then later the other is shaded, it is a problem. With 6 or 8 panels, you could parallel the panels where the shade will pan across, and series that group with another parallel group that has the shade pan across. This way the amount of full sun panels in each of the series sections is about equal. And you might get a bit more total energy if you parallel in that 7th panel on the group that usually sees a bit more shade. That would be 4 in parallel with some shade, in series with only 3 in parallel but with less shade. Not ideal, but it could work well. This does limit your maximum current to about 3P or 34.09 amps. That is too much for #10, and borderline for #8. I would probably run 2 runs of #8 to reduce losses on a 70 foot run. Your voltage doubles to 100.8 VOC and 82.2 VMP. Those seem well in range of an MPPT 150|100 with nearly 50% voltage headroom. You did not mention your battery voltage, so I can't tell if your current is safe. 400 * 6 = 2400 watts max (The 7th panel in this setup can't really make more power, but it could extend the time you get full power with one of the parallel panels being shaded. On a 12 volt system, 2400 watts would be 200 amps, not good. On 24 volts, it is 100 amps, so just making it on the 100 amp rated controller. At 48 volts, it drops to just 50 amps so you would have room to spare. You would have to look up to see if the Victron is able to handle over paneling on the 12 volt setup, the 24 and 48 should be completely fine.