fleet battles with dread lord ships in campaign

Do you mean it doesn't show the battle screen, it just shows them fighting in space?  There's another setting in the options that only shows fleet battles when both sides are fleets-uncheck that and it should fix it.

Attacking and defending makes no difference in DA/TA, except if you're the Arceans.

You haven't provided enough information for me to specifically address your questions, but you might have a look at combat mechanics.

Well, I suppose what I'm asking is about a scenario where a group of small ships with say little to no defence attacks with 36 damage a single ship with 32 hp, will they all fire at once and deal the full 36 to the target? becasue it is seeming that in the 3 against 1 that only one of my three ships is firing before the one ship destroys the entire fleet. So my final question is then, in this situation, is it better not to use fleets and to just send one ship at a time?

Attack rolls from luck*weapon max (in the absence of luck, this is zero) to weapon max, so, no, not really.  On average, 36 attack will do very close to 18 damage.  In general, against a defenseless target, having 36 attack combined on 3 ships will give you a higher chance of doing x amount of damage than having 36 attack on one ship, but it's still going to average around 18 (theoretically, your mileage will vary for "short" battles").

You didn't answer my question, though-you say it "seems" like only one of your ships fired, which makes me think you didn't watch the battle screen, which makes me think you have it only set for fleet on fleet action...which this wasn't.

In DA/TA, though, even if your ships were destroyed in the first round (and ignoring the fact that you were the attacker), each one of them would get a chance to fire.  How much damage they do is another thing entirely.

Your final question is a difficult one to answer, and it depends largely on what the DL ship is.  If it has more attack than your ships, which is likely, then sending a single ship against it, you'll practically never win.  (DA introduced a "tie rule" thanks to simulating simultaneous firing, whereby if after 50 rounds both sides are still alive, only the ship with the highest attack survives.  For combat involving a fleet, this is 300 rounds, but the same principle applies.)  However, it's also unlikely that the DL ship in question has a mere 2 weapons, so 3 ships isn't going to be enough.  (If for instance the DL ship has 9 weapons, it can kill a maximum of 9 ships in the first round of combat, assuming it OHKOs all of them.  As such, using ten ships will eventually defeat the tie rule.)

Almost forgot: Click on an enemy ship and click the little i button for the intelligence report.  You can also get to it if it's a fleet by clicking details first.

I don't have TA, so I delayed in contributing a reply, in hopes someone else would mention one element.

In the original posted question were the words "and no gun defense".  In DA (DL's same, I think), if a ship has no gun defense and is attacked by guns, the ship still gains some defense to guns with either shields or anti-missile defenses.  The defense value in such situations is the square root of the non-armor value.

Thus, if the DL ship had, say, 16 value defense in shields and was attacked with guns, the DL ship would have a defense value of 4.

Is it the same in TA?

If so, that also may explain why the DL ship takes less damage than you expected.

Good point.  Somehow I assumed the OP meant "no defenses".

Yes, this is the same in TA.