The 31-year-old former Ipswich and Burnley player became Buddies boss Danny Lennon's third summer recruit when completing a one-year deal on Thursday.
Skipper Goodwin believes despite the departure of Dutch hit man Nigel Hasselbaink to St Johnstone, with Saints grabbing former Newcastle striker Lewis Guy, the Paisley men will now be far more potent up top.
He said: "I have played against big Sam in England and Scotland and he is a real handful.
"I think he is a very shrewd addition for us and will certainly add something different up top.
"The manager now has the option to go with two powerful strikers if he partners Sam with Stevie Thompson.
"I imagine that would be a pairing that would give any defence in the SPL a tough time.
"With Lewis Guy in and supplying a different option again, and Dougie Imrie also here, we now have four strikers who all give us something different.
"However, the SPL campaign is long and demanding and now we also have the ability to rotate.
"You look at big Stevie Thompson.
"He played over 40 games for us last season which is very demanding for a guy at 32, especially when you consider big Thommo's work rate.
"So now with Sam in, if the gaffer feels Stevie needs a break or one of the other lads then he has that option.
"It is great that we have some real depth about us."
However, following the departure of Jeroen Tesselaar, who knocked back a new two-year deal with the Buddies to sign for SPL rivals Kilmarnock, boss Lennon is still looking for left-sided defensive cover and Saints Goodwin admits a new signing in that area would be a plus.
He said: "It was disappointing Jeroen did not decide to sign the new deal he was offered but that is football.
"He was one of our most consistent players last season and he is only going to get better given his age.
"However, he is gone now and, hopefully, the manager has some irons in the fire in that respect."
But with Parkin joining Guy and ex-Cowdenbeath midfielder Jon Robertson, Goodwin has no doubt that the new recruits will have a positive impact in Paisley next term.
He said: "The manager has made some great signings during his two years at the club.
"I think the lads he has brought in so far will all strengthen us in key places.
"People may look at them and say they are not big names, but when you look at what we got out of Jeroen and Nigel last season, and the way the gaffer moulded them into the team, it underlines what a great eye for talent he has.
"Fingers crossed there will be a couple more new arrivals before we come back in for pre-season."
