What type of athlete are we talking about? Your example could be used, either early in the L-to-S model for a 100/200 type, middle for a 200/100 type and later in a 400/200 type but it would probably occur in SPP2 of a S-to-L plan for a 200 or 200/400 type after the indoor competition season.
The exact location within the SPP would be determined by working backwards through the SPP from the comp date and deciding how far up in distance the SPP will go.
[I assume you mean 2 x (3 x 70) with full recovery between sets]