Not true at all, the injection to carbs is like putting a lawnmower engine in a F1 in real terms ie a serious backward step, but up to you.
As the fuelling will be totally different now with carbs instead of injection, the ignition curve will be totally different.
It will run on the old ignition map on ther std ecu, but nothing remotely like it's full potential, particularly low down with low air speed through carbs.
Without a doubt get a ignition ecu, or you are just wasting your money.
The one you have shown(if they are any good) will do the job, as a rough rule you will need loads more initial advance but less total, but no doubt in the future you will want to add tune up bits so need the adjustability that the ecu gives you.
Unbeleivably some makers still use MECHANICAL advance retard dizzies ie TVR, my god that is from the dark ages, little wonder they love aftermarket ecu's that control the timing.
tabetha