The Springburn club boast the best defensive record in the West Region outfit and former centre-back Smith points to his towering double act as the reason.
He said: "One cannot overlook the contributions of full-back types Graham Girvan, Kenny Hadden and Craig Palmer when looking at our overall defensive stats.
"But you can almost see the confidence coursing through those same guys when our backline has them either side of Ryan and Ross who are inspirational characters and big players for us in every sense.
"We will need them at the top of their game tomorrow as reports reckon Glens striker Gareth Armstrong is on a good run of form and gave Ashfield's defence a really torrid time of it last weekend.
"But without wanting to tempt fate I'd like to think Bo's aggressive and bustling style will not ruffle our pair."
Of greater concern to Smith and co-gaffer Willie Patterson is who will score the goals at the other end of the pitch if their feted rearguard chalks up its seventh clean sheet in eight outings.
Smith added: "We created several openings early on against Shotts Bon Accord last week but failing to take our chances led to us tailing off second half.
"Joe Barclay came off the bench and looked excellent so maybe the time is right to throw him in and see if his nose for goal is greater than the other strikers."
Full-back Palmer, preparing to undergo surgery to mend a dislocated shoulder problem this week, is unlikely to be risked but otherwise Petershill are at full strength for facing the buoyant Ayrshiremen, who are off the bottom of the table and seeking to extend their unbeaten run to four games.
Boss Darren Henderson welcomes back suspension-free defender Danny Mitchell but is unlikely to make changes to his successful line-up.
Smith is not going to be dragged into the hugely topical debate about refereeing standards at Junior level sparked by Ashfield gaffer Stevie Rankin in SportTimes earlier this week.
No stranger to falling foul of officialdom during his own playing days, Smith conceded: "Nobody, least of all myself, should expect to agree with every refereeing decision made during games but it's not a clarification of the rules that's needed as much as an explanation for the obvious change in referees' attitude towards players, coaches and managers this season.
"If Stevie ever manages to get a John Fleming seminar off the ground then you can count me in."
Another well-known dugout figure declaring his interest in meeting up with the SFA Head of Refereeing Development is Pollok No.2 Stevie Docherty, who is still reeling from being handed a six-game ban for receiving the equivalent of two red cards in last week's 2-2 draw with Rob Roy.
Docco's suspension also precludes him from being in the vicinity of Lok's dressing room for an hour before and after games.
He said: "Something has to be done and soon – be it a meeting with John Fleming or a body of current referees – because otherwise the day is coming when teams won't be left with enough players to fulfil their fixtures."
In the Super First Division, table-toppers Kello Rovers have agreed to listen to offers for centre-back Craig Muir and midfielder Jamie Baird, who are thought to have asked away after growing disenchanted over failing to command regular starting jerseys.
Meanwhile, a surprise transfer swoop by title challengers Rutherglen Glencairn has seen journeyman striker Paddy Flannery join up at the Clyde Gateway Stadium from Hurlford United. The Ru'glonian outfit have also fixed up promising amateur full-back Stephen Baillie.