I'll do the math for you. Here is a breakdown of how much potency Sage is capable of delivering in a span of 2 minutes:
Dosis III - 360 potency / Spammable
E. Dosis III - 75 potency (750 potency total) / per 30 seconds
Phlegma III - 600 potency / 40 second cooldown
Psyche - 600 potency / 60 second cooldown
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Total Possible (optimal) casts over 2 minutes:
Dosis III - 41 casts = 14760 potency
E. Dosis III - 4 casts = 3000 potency
Phlegma III - 3 casts = 1800 potency
Psyche - 2 casts (OGCD) = 1200 potency
Total = 48 casts / 20760 potency
Now, using the above suggestions and applying all of them, we need to make a few adjustments for balance. So let's assume that Eukrasian Dosis III's DOT is increased to 95 to compensate for the shorter duration and Eukrasian Dyskrasia's DOT is decreased slightly to 35 potency per tic to make it closer to Dosis III's potency. With this in mind, I'm going to show you how Sage's potency breakdown looks when we change Dosis III to 280 potency and Toxikon II to 420 potency. Naturally, Pneuma would also change to 280 in this example.
Dosis III - 280 potency / Spammable
E. Dosis III - 95 potency (475 potency total) / per 15 seconds
E. Dyskrasia - 25 potency (350 potency total) / per 30 seconds
Phlegma III - 600 potency / 20 second cooldown
Psyche - 600 potency / 30 second cooldown
Toxikon II - 420 potency / Requires Addersting procs
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Total Possible (optimal) casts over 2 minutes:
Dosis III - 24 casts = 6720 potency
E. Dosis III - 8 casts = 3800 potency
E. Dyskrasia - 4 casts = 1400 potency
Phlegma III - 6 casts = 3600 potency
Psyche - 4 casts (OGCD) = 2400 potency
Toxikon II - 6* casts = 2520 potency *Average based on proc chance
Total = 48 casts / 20440 potency
Notice how Sage's total possible potency actually is lower than current Sage's by a total of 320 potency. This would be to compensate not only for the chance to generate more than 6 Adderstings per 2 minutes (which keep in mind you might also generate less), but also the added potential of buff windows. Do you want to know how far you missed the ballpark with your guestimate of Dosis at 100 potency to compensate for these changes? Your Sage balancing would result in Sage doing up to around 2400 potency with Dosis casts, and 900 for Toxikon casts, resulting in a total possible potency per 2 minutes of 14500, which is less damage than what Astrologian does per 2 minutes without buffs.
To be frank, I do not care at all whether or not you like or don't like this play style. Because I don't think every healer should play this way. You can have a healer that plays the way you like, just let me have 1 healer that plays the way I like. Since Sage was given the identity of a DPS healer, then let it actually play into a more offensive play style.