They drengin should beat you just like that if they have a kinetic augment. You also don't know if they have any other hidden advantages (accuracy, range, and cooldown of weapons) that they could easily accumulate through tech to beat you easily with ships of comparable stats.

Upgrade costs are calculated in some way we don't know based on the component differences between designs. If two ship designs are very similar it's very cheap.

Yes, sentry is useless. The notification screen is the only real option, and even that is bad for the purpose.

I would also note that the damage dealt per shot has a random component to it. It's entirely possible that the Drengin ships did not have any invisible bonuses such as the Rapid Reload component and yet still won. Statistical advantages only make it more likely that you'll win, and that you'll win by a larger margin than your opponent would have, they don't guarantee that you will win, and the smaller the statistical adantages are, the less favorable the odds of winning are and the smaller the margin of victory is likely to be (though as long as you do have the statistical advantage, the odds are still in your favor).

Also note that the ship tool tips you provide as evidence for the statistical superiority of your ships do not show several of the statistics which could impact battle performance - nominal weapon accuracy, jamming (essentially nominal dodge chance), weapon range, weapon rate of fire, defense bypass, and defense damage are all bonuses that the game offers, and yet not one of these appears in the tool tips shown nor would they be shown in the tool tips were they present on the ships. If the only such modifier in play comes from the Rapid Reloader (which increases mass driver rate of fire by 100% and reduces mass driver accuracy by 0.15), and the Drengin ships have it but yours do not, then a more accurate attack score for your ships is 6.4 gun DPS (32 attack score * 80% hit rate against unjammed targets / 4 s firing interval) and a more accurate attack score for the Drengin ships is 8.125 gun DPS (25 attack score * 65% hit rate against unjammed targets / 2 s firing interval). That's a considerably different picture from what the simple attack scores would suggest - by the attack scores, it looks like your ships are better; theoretical time-average DPS, however, would say otherwise - and the only thing that needs to be true is for the Drengin ships to carry one component that yours do not, a component which moreover modifies no statistic covered by any tool tip visible outside the design screen.

I agree it definitely looks like the Drengi ship has kinetic rate of fire component (Rapid Reload). Look at the number of shots counter in the summary. The Drengi ship got 23 shots off in the same time the terran ships only got 10 off. They didn't do 2x the damage though which is also in line with the Rapid Reload component (2x rate of fire for 20% less accuracy) still quite a good trade. There are quite a few ship components affecting rate of fire, range accuracy, tactical heal etc... any of which can lead to nasty surprises because they make the strategic map's fleet summary stats deceptive.

I only recently found out that L meant they were augmented. I always thought they were just Longer ranged. You can confirm what they have by checking your basic ships in the ship designer as well!